CIS Oracle Solaris 11 Benchmark - paper.bobylive.com

http://benchmarks.cisecurity.org

CIS Oracle Solaris 11 Benchmark

v1.1.0 - 09-30-2013

http://benchmarks.cisecurity.org/

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Table of Contents Overview .................................................................................................................................................................. 6

Recommendations ............................................................................................................................................. 12

1 Software Installation and Updates ...................................................................................................... 12

1.1 Use the Latest Package Updates (Not Scored) ........................................................................ 12

2 Disable Unnecessary Services ............................................................................................................... 13

2.1 Disable Local-only Graphical Login Environment (Scored) .............................................. 13

2.2 Configure sendmail Service for Local-Only Mode (Scored) ............................................... 14

2.3 Disable RPC Encryption Key (Scored) ....................................................................................... 15

2.4 Disable NIS Server Services (Scored) ......................................................................................... 16

2.5 Disable NIS Client Services (Scored) .......................................................................................... 17

2.6 Disable Kerberos TGT Expiration Warning (Scored) ........................................................... 17

2.7 Disable Generic Security Services (GSS) (Scored) ................................................................. 18

2.8 Disable Removable Volume Manager (Scored) ...................................................................... 19

2.9 Disable automount Service (Scored) .......................................................................................... 19

2.10 Disable Apache Service (Scored) ............................................................................................... 20

2.11 Disable Local-only RPC Port Mapping Service (Scored) .................................................. 21

2.12 Configure TCP Wrappers (Not Scored) ................................................................................... 22

2.13 Disable Telnet Service (Scored) ................................................................................................. 24

3 Kernel Tuning .............................................................................................................................................. 24

3.1 Restrict Core Dumps to Protected Directory (Scored) ........................................................ 24

3.2 Enable Stack Protection (Scored) ................................................................................................ 25

3.3 Enable Strong TCP Sequence Number Generation (Scored) ............................................. 26

3.4 Disable Source Packet Forwarding (Scored) ........................................................................... 27

3.5 Disable Directed Broadcast Packet Forwarding (Scored) .................................................. 28

3.6 Disable Response to ICMP Timestamp Requests (Scored) ................................................ 29

3.7 Disable Response to ICMP Broadcast Timestamp Requests (Scored) .......................... 30

3.8 Disable Response to ICMP Broadcast Netmask Requests (Scored) ............................... 30

3.9 Disable Response to Broadcast ICMPv4 Echo Request (Scored)..................................... 31

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3.10 Disable Response to Multicast Echo Request (Scored) .................................................... 32

3.11 Ignore ICMP Redirect Messages (Scored) .............................................................................. 33

3.12 Set Strict Multihoming (Scored) ................................................................................................ 33

3.13 Disable ICMP Redirect Messages (Scored) ............................................................................ 34

3.14 Disable TCP Reverse IP Source Routing (Scored) ............................................................... 35

3.15 Set Maximum Number of Half-open TCP Connections (Scored) ................................... 36

3.16 Set Maximum Number of Incoming Connections (Scored) ............................................. 37

3.17 Disable Network Routing (Scored) ........................................................................................... 37

4 Auditing and Logging................................................................................................................................ 39

4.1 Create CIS Audit Class (Scored) .................................................................................................... 39

4.2 Enable Auditing of Incoming Network Connections (Scored) .......................................... 40

4.3 Enable Auditing of File Metadata Modification Events (Scored) ..................................... 40

4.4 Enable Auditing of Process and Privilege Events (Scored) ............................................... 41

4.5 Configure Solaris Auditing (Scored) ........................................................................................... 43

5 File/Directory Permissions/Access .................................................................................................... 44

5.1 Default Service File Creation Mask (Scored) ........................................................................... 44

5.2 Set Sticky Bit on World Writable Directories (Not Scored) ............................................... 45

6 System Access, Authentication, and Authorization ...................................................................... 46

6.1 Disable login: Services on Serial Ports (Scored) .................................................................... 46

6.2 Disable "nobody" Access for RPC Encryption Key Storage Service (Scored) ............. 47

6.3 Disable X11 Forwarding for SSH (Scored) ............................................................................... 48

6.4 Limit Consecutive Login Attempts for SSH (Scored) ............................................................ 49

6.5 Disable Rhost-based Authentication for SSH (Scored)........................................................ 49

6.6 Disable root login for SSH (Scored) ............................................................................................ 50

6.7 Blocking Authentication Using Empty/Null Passwords for SSH (Scored) .................. 51

6.8 Disable Host-based Authentication for Login-based Services (Scored) ....................... 52

6.9 Restrict FTP Use (Scored) ............................................................................................................... 52

6.10 Set Delay between Failed Login Attempts to 4 (Scored) .................................................. 54

6.11 Remove Autologin Capabilities from the GNOME desktop (Scored) ........................... 54

6.12 Set Default Screen Lock for GNOME Users (Scored) .......................................................... 55

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6.13 Restrict at/cron to Authorized Users (Scored) .................................................................... 56

6.14 Restrict root Login to System Console (Scored).................................................................. 57

6.15 Set Retry Limit for Account Lockout (Scored) ..................................................................... 57

6.16 Set EEPROM Security Mode and Log Failed Access (SPARC) (Not Scored) .............. 59

6.17 Secure the GRUB Menu (Intel) (Scored) ................................................................................. 60

7 User Accounts and Environment ......................................................................................................... 61

7.1 Set Password Expiration Parameters on Active Accounts (Scored) .............................. 61

7.2 Set Strong Password Creation Policies (Scored) ................................................................... 63

7.3 Set Default umask for users (Scored) ......................................................................................... 64

7.4 Set Default File Creation Mask for FTP Users (Scored) ....................................................... 65

7.5 Set "mesg n" as Default for All Users (Scored)........................................................................ 66

7.6 Lock Inactive User Accounts (Scored) ....................................................................................... 67

8 Warning Banners ....................................................................................................................................... 68

8.1 Create Warnings for Standard Login Services (Scored) ..................................................... 68

8.2 Enable a Warning Banner for the SSH Service (Scored) ..................................................... 69

8.3 Enable a Warning Banner for the GNOME Service (Scored) ............................................. 70

8.4 Enable a Warning Banner for the FTP service (Scored) ..................................................... 70

8.5 Check that the Banner Setting for telnet is Null (Scored) ............................................. 71

9 System Maintenance ................................................................................................................................. 72

9.1 Check for Remote Consoles (Scored) ......................................................................................... 72

9.2 Verify System File Permissions (Not Scored) ......................................................................... 73

9.3 Verify System Account Default Passwords (Scored) ............................................................ 74

9.4 Ensure Password Fields are Not Empty (Scored) ................................................................. 75

9.5 Verify No UID 0 Accounts Exist Other than root (Scored) ................................................. 75

9.6 Ensure root PATH Integrity (Scored) ......................................................................................... 76

9.7 Check Permissions on User Home Directories (Scored)..................................................... 77

9.8 Check Permissions on User "." (Hidden) Files (Scored) ..................................................... 78

9.9 Check Permissions on User .netrc Files (Scored) .................................................................. 78

9.10 Check for Presence of User .rhosts Files (Scored) .............................................................. 79

9.11 Check Groups in passwd(4) (Scored) ...................................................................................... 80

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9.12 Check That Users Are Assigned Home Directories (Scored) .......................................... 80

9.13 Check That Defined Home Directories Exist (Scored) ...................................................... 81

9.14 Check User Home Directory Ownership (Scored) .............................................................. 82

9.15 Check for Duplicate UIDs (Scored) ........................................................................................... 83

9.16 Check for Duplicate GIDs (Scored) ........................................................................................... 83

9.17 Check That Reserved UIDs Are Assigned to System Accounts (Scored) .................... 84

9.18 Check for Duplicate User Names (Scored) ............................................................................. 85

9.19 Check for Duplicate Group Names (Scored) ......................................................................... 86

9.20 Check for Presence of User .netrc Files (Scored) ................................................................ 86

9.21 Check for Presence of User .forward Files (Scored) .......................................................... 87

9.22 Find World Writable Files (Not Scored) ................................................................................. 88

9.23 Find SUID/SGID System Executables (Not Scored) ........................................................... 88

9.24 Find Un-owned Files and Directories (Scored) ................................................................... 89

9.25 Find Files and Directories with Extended Attributes (Scored) ..................................... 90

10 Appendix A: Additional Security Notes ......................................................................................... 91

10.1 SN.1 Restrict access to suspend feature (Not Scored) ................................................ 91

10.2 SN.2 Remove Support for Internet Services (inetd) (Not Scored) ......................... 92

Appendix: Change History .............................................................................................................................. 93

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Overview

This document, CIS Oracle Solaris 11 Benchmark v1.1.0, provides prescriptive guidance for establishing a secure configuration posture for Oracle Solaris 11 on both x86 and SPARC platforms. This guide was tested against Solaris 11 11/11 release, updated to the Software Repository Update 5 (SRU5). As of the publication of this document, Solaris 11 11/11 SRU5 is the latest available support update for the Solaris 11 OS. The recommendations included in this document may need to be adjusted for future Solaris 11 updates. To obtain the latest version of this guide, please visit http://benchmarks.cisecurity.org. If you have questions, comments, or have identified ways to improve this guide, please write us at [email protected].

Intended Audience

This document is intended for system and application administrators, security specialists, auditors, help desk, and platform deployment personnel who plan to develop, deploy, assess, or secure solutions that incorporate Oracle Solaris 11.

Consensus Guidance

This benchmark was created using a consensus review process comprised subject matter experts. Consensus participants provide perspective from a diverse set of backgrounds including consulting, software development, audit and compliance, security research, operations, government, and legal. Each CIS benchmark undergoes two phases of consensus review. The first phase occurs during initial benchmark development. During this phase, subject matter experts convene to discuss, create, and test working drafts of the benchmark. This discussion occurs until consensus has been reached on benchmark recommendations. The second phase begins after the benchmark has been published. During this phase, all feedback provided by the Internet community is reviewed by the consensus team for incorporation in the benchmark. If you are interested in participating in the consensus process, please visit https://community.cisecurity.org.

http://benchmarks.cisecurity.org/

mailto:[email protected]

https://community.cisecurity.org/

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Typographical Conventions

The following typographical conventions are used throughout this guide:

Convention Meaning Stylized Monospace font Used for blocks of code, command, and script examples.

Text should be interpreted exactly as presented. Monospace font Used for inline code, commands, or examples. Text should

be interpreted exactly as presented. <italic font in brackets> Italic texts set in angle brackets denote a variable

requiring substitution for a real value. Italic font Used to denote the title of a book, article, or other

publication.

Note Additional information or caveats

Scoring Information

A scoring status indicates whether compliance with the given recommendation impacts the

assessed target's benchmark score. The following scoring statuses are used in this

benchmark:

Scored Failure to comply with "Scored" recommendations will decrease the final benchmark score. Compliance with "Scored" recommendations will increase the final benchmark score.

Not Scored Failure to comply with "Not Scored" recommendations will not decrease the final benchmark score. Compliance with "Not Scored" recommendations will not increase the final benchmark score.

Profile Definitions

The following configuration profiles are defined by this Benchmark:

Level 1

Items in this profile intend to:

o be practical and prudent; o provide a clear security benefit; and o not inhibit the utility of the technology beyond acceptable means.

Level 2

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This profile extends the "Level 1" profile. Items in this profile exhibit one or more of the following characteristics:

o are intended for environments or use cases where security is paramount o acts as defense in depth measure o may negatively inhibit the utility or performance of the technology.

Acknowledgements

This benchmark exemplifies the great things a community of users, vendors, and subject matter experts can accomplish through consensus collaboration. The CIS community thanks the entire consensus team with special recognition to the following individuals who contributed greatly to the creation of this guide:

Author

David McMillan

Glenn Brunette , Oracle Corporation

Gary Winiger

Contributor

David Kennel , U.S. Dept. of Energy

Joe Wulf RHCSA(RHEL6), FITSP-D, CISSP, VCP3, CPO(USN RET), U.S. National Security

Agency

John Banghart

John Traenkenschuh

Keith Buck

Larry Cole

Mark Phillips

Nancy Whitney

Ralph Durkee CISSP, GSEC, GCIH, GSNA, GPEN, Durkee Consulting, Inc.

Zack Yang

Liang Qin

Blake Frantz , Center for Internet Security

Carole Fennelly

Chris Cook , Cable & Wireless Worldwide

Damian Southard

David Pollard , National Aeronautics and Space Administration

Doug Schmidt

Filip Francis

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Glenn Brunette , Oracle Corporation

Jason Mackanick , Defense Information Systems Agency (DISA)

Jay Beale

Nelson Benitez

Vladimir Bogodist

Wilfred Artman

The CIS community also extends thanks to those that contributed to previous versions of this Benchmark:

Adam Montville, Andrew Gilmore, Blake Frantz, Carole Fennelly, Chris Cook, Christopher Calabrese, Damian Southard, Dave Shackleford, David A. Kennel, David Pollard, Douglas J Schmidt, Filip Francis, Glenn Brunette, Hal Pomeranz, Hoang Truong Dinh, Ian J Hunt, Jason Mackanick, Jay Beale, Joe Wulf, Joel Kirch, John Banghart, John Jenkinson, John Traenkenschuh, Jonathan Klein, Keith Buck, Larry Cole, Mark Phillips, Mike Bamford, Nancy Whitney, Nelson Benitez, Ralph Durkee, Randy Young, Timothy Wood, Tom Maloy, Tom Rhodes, Vladimir Bogodist, Wilfred Artman, and Zack Yang

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Assumptions

OS Platform

The recommendations and actions described in this document are based upon an installation of the Solaris 11 OS that includes both the solaris-desktop and solaris-large-server software package groups. Some of the actions described in this document will not apply to systems that are installed using different package or package group combinations including those that have been minimized. To determine if a system has the solaris-desktop and solaris-large-server software package groups installed, use the command:

# pkg list -Hs \*group\* | awk '{ print $1 }'

group/system/solaris-desktop

group/system/solaris-large-server

System State

It is recommended that all remediation actions be applied when the system is in a “quiet” state - one in which application and third party software and services are not active. Hardening services that may be in use can have unpredictable results. If possible, perform the auditing actions when the system is running in “fully networked, multi-user user mode” so that all applications and services on the host will be operating in the correct posture to determine run-time compliance failures.

Test Actions

It is strongly recommended that all actions be first executed on a test or non-critical system before being performed on a production server. While the actions described in this document have been tested, there is no way to predict with certainty how they will affect a given environment.

Shell Environment

The actions listed in this document are written with the assumption that they will be executed in the root (or privilege equivalent) role running the /bin/bash shell and without noclobber set.

Order of Operations

The actions listed in this document are written with the assumption that they will be executed in the order presented here. Some actions may need to be modified if the order is changed. Actions are written so that they may be copied directly from this document into an appropriate shell window with a "cut-and-paste" operation.

Backup Key Files

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Before performing the steps of this benchmark, it is strongly recommended that administrators create an alternate boot environment for backup purposes. This allows an administrator to return to the original configuration should anything go wrong while applying the recommendations contained in this document. To create a clone of the current boot environment, run the command:

# beadm create solaris-cis-backup

If a problem does occur requiring the system to be reset to its saved state, simply select the backup boot environment, solaris-cis-backup, from the the boot menu. Once the system has successfully booted, use the following command to activate the saved boot environment so that it is automatically used for future reboots:

# beadm activate solaris-cis-backup

For more information on using and managing Solaris 11 boot environments, see the Oracle Solaris 11 product documentation.

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Recommendations

1 Software Installation and Updates

The Solaris 11 OS should be periodically updated to enable the support of new hardware platforms as well as enhance the security, reliability, and performance of the system.

1.1 Use the Latest Package Updates (Not Scored)

Profile Applicability:

Level 1

Description:

The Solaris 11 OS should be periodically updated to install or upgrade software packages that will enhance the security, reliability, and performance of the system.

Rationale:

For the Solaris 11 OS, there will be no more software patches issued, but rather security and other improvements will be installed by updating one or more software packages.

Audit:

To verify that the system is operating with the latest software updates, perform the following and verify that the result is as shown:

# pkg update -n

No updates available for this image.

In addition, you can manually verify the update associated with the running system using the following command. The output of this command will indicate the operation system version and update number as well as the Software Repository Update (SRU) number.

# pkg info entire | grep FMRI: | awk '{ print $2 }'

pkg://solaris/[email protected],5.11-0.175.0.5.0.5.0:20120320T213737Z

From this string, it is possible to determine:

the Oracle Solaris release: 5.11 (0.5.11,5.11-0.175.0.5.0.5.0:20120320T213737Z) the Oracle Solaris Update: 0 (0.5.11,5.11-0.175.0.5.0.5.0:20120320T213737Z) the Oracle Solaris SRU: 5 (0.5.11,5.11-0.175.0.5.0.5.0:20120320T213737Z)

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For more information, see the Oracle white paper titled "Packaging and Delivering Software with the Image Packaging System" available from: http://hub.opensolaris.org/bin/download/Project+pkg/files/ipsdevguide.pdf.

Remediation:

Run the following command to refresh the package catalog, download and apply any available updates:

# pkg update

2 Disable Unnecessary Services

While using the most up to date software packages will help to correct any known vulnerabilities, one of the best ways to protect the system against as yet unreported vulnerabilities is to disable services that are not required for that particular system's intended operation or management. This helps to prevent the exploitation of vulnerabilities that may be discovered at a later date. The actions in this section of the document provide guidance on what services can be safely disabled and under which circumstances.

The Solaris 11 OS has implemented a "Secure by Default" (SBD) posture whereby many services that were once automatically enabled are now either disabled or configured to listen only for connections originating from the system itself. This default software configuration greatly simplifies many of the security hardening steps typically undertaken in previous versions of the operating system. As a result, this section will build upon this default configuration and focus specifically on those services that are enabled (local-only or otherwise) that organizations may want to disable.

As noted above, several services are not disabled, but rather are placed into a "local only" mode

where they will accept connections originating only from the local system itself. This was done

to strike a balance between security and out-of-the-box usability. If these services are not

required, it is recommended that they be disabled to guard against potential future vulnerabilities

that can be exploited by users and/or services that are operating locally on the system.

2.1 Disable Local-only Graphical Login Environment (Scored)


Level 1

Description:

http://hub.opensolaris.org/bin/download/Project+pkg/files/ipsdevguide.pdf

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The graphical login service provides the capability of logging into the system using an X-windows type interface from the console. If graphical login access for the console is required, leave the service in local-only mode.

Rationale:

This service should be disabled if it is not required.

Audit:

Perform the following and verify that the result is as shown:

# svcs -Ho state svc:/application/graphical-login/gdm:default

disabled

If gdm is not installed, this will return an error, or no output. This is also considered a passing state.

Remediation:

To disable this service, run the following command:

# svcadm disable svc:/application/graphical-login/gdm:default

2.2 Configure sendmail Service for Local-Only Mode (Scored)


Level 1

Description:

In Solaris 11, the sendmail service is set to local only mode by default. This means that users on remote systems cannot connect to the sendmail service, eliminating the possibility of a remote exploit attack against some future sendmail vulnerability. Leaving sendmail in local-only mode permits mail to be sent out from the local system. If the local system will not be processing or sending any mail, this service can be disabled.

However, if sendmail is disabled completely, email messages sent to the root account (such as cron job output or audit service warnings) will fail to be delivered.

An alternative approach is to disable the sendmail service and create a cron job to process all mail that is queued on the local system, sending it to a relay host defined in the sendmail.cf file. It is recommended that sendmail be left in local-only mode unless there is a specific requirement to completely disable it.

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Rationale:

The software for all Mail Transfer Agents is complex and most have a long history of security issues. While it is important to ensure that the system can process local mail messages, it is not necessary to have the MTA's daemon listening on a port unless the server is intended to be a mail server that receives and processes mail from other systems.

Audit:

Perform the following command and make sure that the MTA is listening on the loopback address (127.0.0.1):

# netstat -an | grep LIST | grep ":25[[:space:]]"

tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN

Remediation:

Run the following to set sendmail to listen only local interfaces:

# svccfg -v -s svc:/network/smtp:sendmail setprop config/local_only=false

# svcadm refresh sendmail

# svcadm restart sendmail

2.3 Disable RPC Encryption Key (Scored)


Level 1

Description:

The keyserv service is only required for sites that are using the Secure RPC mechanism. The most common use for Secure RPC on Solaris machines is "secure NFS", which uses the Secure RPC mechanism to provide higher levels of security than the standard NFS protocols. ("Secure NFS" is unrelated to Kerberos authentication as a mechanism for providing higher levels of NFS security. "Kerberized" NFS does not require the keyserv service to be running.)

Rationale:


Audit:


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# svcs -Ho state svc:/network/rpc/keyserv

disabled

Remediation:


# svcadm disable svc:/network/rpc/keyserv

2.4 Disable NIS Server Services (Scored)


Level 1

Description:

The NIS server software is not installed by default and is only required on systems that are acting as an NIS server for the local site. Typically there are only a small number of NIS servers on any given network. These services are disabled by default unless the system has been previously configured to act as a NIS server.

Rationale:

As RPC-based services such as NIS may use non-secure authentication and share sensitive network object information with systems and applications using RPC-based services, this service should be disabled. Users are encouraged to use LDAP as a name service in place of NIS.

Audit:


# svcs -Ho state svc:/network/nis/server

disabled

# svcs -Ho state svc:/network/nis/domain

disabled

Remediation:

To disable this service, run the following commands:

# svcadm disable svc:/network/nis/server

# svcadm disable svc:/network/nis/domain

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2.5 Disable NIS Client Services (Scored)


Level 1

Description:

If the local site is not using the NIS naming service to distribute system and user configuration information, this service may be disabled. This service is disabled by default unless the NIS service has been installed and configured on the system.

Rationale:

As RPC-based services such as NIS may use non-secure authentication and share sensitive network object information with systems and applications using RPC-based service, NIS client daemons should be disabled. Users are encouraged to use LDAP as a name service in place of NIS.

Audit:


# svcs -Ho state svc:/network/nis/client

disabled

# svcs -Ho state svc:/network/nis/domain

disabled

Remediation:


# svcadm disable svc:/network/nis/client

# svcadm disable svc:/network/nis/domain

2.6 Disable Kerberos TGT Expiration Warning (Scored)


Level 1

Description:

The Kerberos TGT warning service is used to warn users when their Kerberos tickets are about expire or to renew those tickets before they expire. This service is not used if Kerberos has not been configured. This service is configured to be "local only" by default.

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Rationale:


Audit:


# svcs -Ho state svc:/network/security/ktkt_warn

disabled

Remediation:


# svcadm disable svc:/network/security/ktkt_warn

2.7 Disable Generic Security Services (GSS) (Scored)


Level 1

Description:

The GSS API is a security abstraction layer that is designed to make it easier for developers to integrate with different authentication schemes. It is most commonly used in applications for sites that use Kerberos for network authentication, though it can also allow applications to interoperate with other authentication schemes.

Rationale:

GSS does not expose anything external to the system as it is configured to use TLI (protocol = ticotsord) by default. This service should be disabled if it is not required.

Audit:


# svcs -Ho state svc:/network/rpc/gss

disabled

Remediation:


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# svcadm disable svc:/network/rpc/gss

2.8 Disable Removable Volume Manager (Scored)


Level 1

Description:

The HAL-aware removable volume manager in the Solaris 11 OS automatically mounts external devices for users whenever the device is attached to the system. These devices include CD-R, CD-RW, floppies, DVD, USB and 1394 mass storage devices. See the rmvolmgr(1M) manual page for more details.

Rationale:

Allowing users to mount and access data from removable media devices makes it easier for malicious programs and data to be imported onto the network. It also introduces the risk that sensitive data may be transferred off the system without a log record. By adding rmvolmgr to the .xinitrc file, user-isolated instances of rmvolmgr can be run via a session startup script. In such cases, the rmvolmgr instance will not allow management of volumes that belong to other than the owner of the startup script. When a user logs onto the workstation console (/dev/console), any instance of user-initiated rmvolmgr will only own locally connected devices, such as CD-ROMs or flash memory hardware, locally connected to USB or FireWire ports.

Audit:


# svcs -Ho state svc:/system/filesystem/rmvolmgr

disabled

# svcs -Ho state svc:/network/rpc/smserver

disabled

Remediation:


# svcadm disable svc:/system/filesystem/rmvolmgr

# svcadm disable svc:/network/rpc/smserver

2.9 Disable automount Service (Scored)


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Level 1

Description:

The automount daemon is normally used to automatically mount NFS file systems from remote file servers when needed. However, the automount daemon can also be configured to mount local (loopback) file systems as well, which may include local user home directories, depending on the system configuration.

Rationale:


Audit:


# svcs -Ho state svc:/system/filesystem/autofs

disabled

Remediation:


# svcadm disable svc:/system/filesystem/autofs

2.10 Disable Apache Service (Scored)


Level 1

Description:

The Apache service provides an instance of the Apache web server.

Rationale:


Audit:


# svcs -Ho state svc:/network/http:apache22

disabled

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Remediation:


# svcadm disable svc:/network/http:apache22

References:

1. Apache Benchmark and scoring tool from CIS, http://www.cisecurity.org/bench_apache.html

2. Apache Foundation's "Security Tips" document http://httpd.apache.org/docs-2.0/misc/security_tips.html

2.11 Disable Local-only RPC Port Mapping Service (Scored)


Level 1

Description:

Remote Procedure Call (RPC) is used by many services within the Solaris 11 operating system. Some of these services allow external connections to use the service (e.g. NFS, NIS). By default, the Solaris 11 OS configures this service to be local only.

Rationale:

RPC-based services typically have weak or non-existent authentication and yet may share very sensitive information, which is vulnerable to network traffic sniffers. Unless one of these services is required on this host, RPC-based tools should be fully disabled.

Audit:


# svcs -Ho state svc:/network/rpc/bind

disabled

Remediation:


# svcadm disable svc:/network/rpc/bind

If the goal is to restrict access to this service, but not disable it completely, consider using a host-based firewall such as ipfilter(5) to control what hosts are allowed to access this

http://www.cisecurity.org/bench_apache.html

http://httpd.apache.org/docs-2.0/misc/security_tips.html

http://httpd.apache.org/docs-2.0/misc/security_tips.html

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service. Alternatively, TCP Wrappers support, which controls host access and connection auditing, can be enabled. TCP Wrappers is discussed in the next section.

2.12 Configure TCP Wrappers (Not Scored)


Level 1

Description:

TCP Wrappers is a host-based access control system that allows administrators to control who has access to various network services based on the IP address of the remote end of the connection. TCP Wrappers also provide logging information via syslog about both successful and unsuccessful connections.

Rationale:

TCP Wrappers provides granular control over what services can be accessed over the network. Its logs show attempted access to services from non-authorized systems, which can help identify unauthorized access attempts.

Audit:


# inetadm -p | grep tcp_wrappers

tcp_wrappers=TRUE

# ls /etc/hosts.deny

/etc/hosts.deny

# ls /etc/hosts.allow

/etc/hosts.allow

The above command will check whether TCP Wrappers is enabled for all TCP-based services started by inetd. TCP Wrappers are enabled by default for sendmail and SSH. Individual inetd services may still be configured to use TCP Wrappers even if the global parameter (above) is set to FALSE. To check the status of individual inetd services, use the command:

# for svc in `inetadm | awk '/svc:\// { print $NF }'`; do

val=`inetadm -l ${svc} | grep -c tcp_wrappers=TRUE`

if [ ${val} -eq 1 ]; then

echo "TCP Wrappers enabled for ${svc}"

fi

done

Lastly, TCP Wrappers can be enabled for the RPC port mapping service. To determine if this is the case, use the command:

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# svcprop -p config/enable_tcpwrappers rpc/bind

false

Remediation:

To enable TCP Wrappers, run the following commands:

1. Create and customize your policy in /etc/hosts.allow:

# echo "ALL: <net>/<mask>, <net/<mask>, …" > /etc/hosts.allow

where each <net>/<mask> combination (for example, the Class C address block

"192.168.1.0/255.255.255.0") can represent one network block in use by your

organization that requires access to this system.

2. Create a default deny policy in /etc/hosts.deny:

# echo "ALL: ALL" >/etc/hosts.deny

3. Enable TCP Wrappers for all services started by inetd:

# inetadm -M tcp_wrappers=TRUE

To protect only specific inetd services, use the command:

# inetadm -m [FMRI] tcp_wrappers=TRUE

To enable TCP Wrappers for the RPC port mapping service, use the commands:

# svccfg -s rpc/bind setprop config/enable_tcpwrappers=true

# svcadm refresh rpc/bind

The versions of SSH and sendmail that ship with Solaris 11 will automatically use

TCP Wrappers to filter access if a hosts.allow or hosts.deny file exists. To protect

UDP and RPC-based services that are spawned from inetd, consider implementing a

host-based firewall such as Solaris IP Filter. See ipfilter(5) for more information.

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2.13 Disable Telnet Service (Scored)


Level 1

Description:

The telnet daemon, which accepts connections from users from other systems via the telnet protocol and can be used for remote shell access.

Rationale:

The telnet protocol is insecure and unencrypted. The use of an unencrypted transmission medium could allow a user with access to sniff network traffic the ability to steal credentials. The ssh protocol provides an encrypted session and stronger security.

Audit:

Ensure telnet server is not enabled:

# svcs -Ho state svc:/network/telnet

disabled

Remediation:

Disable telnet server if enabled:

# svcadm disable svc:/network/telnet

3 Kernel Tuning

This section describes additional measures that may be taken to provide protection on the kernel

level.

3.1 Restrict Core Dumps to Protected Directory (Scored)


Level 1

Description:

The action described in this section creates a protected directory to store core dumps and also causes the system to create a log entry whenever a regular process dumps core.

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Rationale:

Core dumps, particularly those from set-UID and set-GID processes, may contain sensitive data.

Audit:


# coreadm

global core file pattern: /var/cores/core_%n_%f_%u_%g_%t_%p

global core file content: default

init core file pattern: core

init core file content: default

global core dumps: enabled

per-process core dumps: disabled

global setid core dumps: enabled

per-process setid core dumps: disabled

global core dump logging: enabled

# ls -ld /var/cores

drwx------ 2 root sys 2 Oct 20 16:35 /var/cores

Remediation:

To implement the recommendation, run the commands:

# chmod 700 /var/cores

# coreadm -g /var/cores/core_%n_%f_%u_%g_%t_%p \

-e log -e global -e global-setid \

-d process -d proc-setid

If the local site chooses, dumping of core files can be completely disabled with the following command:

# coreadm -d global -d global-setid -d process -d proc-setid

3.2 Enable Stack Protection (Scored)


Level 1

Description:

Buffer overflow exploits have been the basis for many highly publicized compromises and defacements of large numbers of Internet connected systems. Many of the automated tools in use by system attackers exploit well-known buffer overflow problems in vendor-supplied and third party software.

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Rationale:

Enabling stack protection prevents certain classes of buffer overflow attacks and is a significant security enhancement. However, this does not protect against buffer overflow attacks that do not execute code on the stack (such as return-to-libc exploits). While most of the Solaris OS is already configured to employ a non-executable stack, this setting is still recommended to provide a more comprehensive solution for both Solaris and other software that may be installed.

Audit:


# grep "^set noexec_user_stack.*=1" /etc/system

set_noexec_user_stack=1

set_noexec_user_stack_log=1

To verify that this setting is in effect on the running system, use the command:

# echo "noexec_user_stack/D" | mdb -k

noexec_user_stack: 1

Remediation:

To enable stack protection and block stack-smashing attacks, run the following to edit the /etc/system file:

# if [ ! "`grep noexec_user_stack= /etc/system`" ]; then

cat <<END_CFG >>/etc/system

set noexec_user_stack=1

set noexec_user_stack_log=1

END_CFG

fi

3.3 Enable Strong TCP Sequence Number Generation (Scored)


Level 1

Description:

The variable TCP_STRONG_ISS defines the mechanism used for TCP initial sequence number generation. If an attacker can predict the next sequence number, it is possible to inject fraudulent packets into the data stream to hijack the session.

Rationale:

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The RFC 1948 method is widely accepted as the strongest mechanism for TCP packet generation. This makes remote session hijacking attacks more difficult, as well as any other network-based attack that relies on predicting TCP sequence number information. It is theoretically possible that there may be a small performance hit in connection setup time when this setting is used, but there are no publicly available benchmarks that establish this.

Audit:

To verify the setting is in effect in the /etc/default/inetinit file, use the command:

# grep "^TCP_STRONG_ISS=" /etc/default/inetinit

TCP_STRONG_ISS=2

To verify this setting is in effect on the running system, use the command:

# ipadm show-prop -p _strong_iss -co current tcp

2

Remediation:

Run the following commands to set the TCP_STRONG_ISS parameter to use RFC 1948 sequence number generation in the /etc/default/inetinit file:

# cd /etc/default

# awk '/TCP_STRONG_ISS=/ { $1 = "TCP_STRONG_ISS=2" }; \

{ print }' inetinit > inetinit.CIS

# mv inetinit.CIS inetinit

To set the TCP_STRONG_ISS parameter on a running system, use the command:

# ipadm set-prop -p _strong_iss=2 tcp

3.4 Disable Source Packet Forwarding (Scored)


Level 1

Description:

This setting controls whether the IPv4 or IPv6 configuration will forward packets with IPv4 routing options or IPv6 routing headers.

Rationale:

Keep this parameter disabled to prevent denial of service attacks through spoofed packets.

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Audit:

To verify this setting for IPv4 packets, use the commands:

# ipadm show-prop -p _forward_src_routed -co current ipv4

0

# ipadm show-prop -p _forward_src_routed -co persistent ipv4

0


# ipadm show-prop -p _forward_src_routed -co current ipv6

0

# ipadm show-prop -p _forward_src_routed -co persistent ipv6

0

Remediation:

To enforce this setting for IPv4 packets, use the command:

# ipadm set-prop -p _forward_src_routed=0 ipv4


# ipadm set-prop -p _forward_src_routed=0 ipv6

3.5 Disable Directed Broadcast Packet Forwarding (Scored)


Level 1

Description:

This setting controls whether Solaris forwards broadcast packets for a specific network if it is directly connected to the machine.

Rationale:

Keep this parameter disabled to prevent denial of service attacks.

Audit:

To verify this setting, use the commands:

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# ipadm show-prop -p _forward_directed_broadcasts -co current ip

0

# ipadm show-prop -p _forward_directed_broadcasts \

-co persistent ip

0

Remediation:

To enforce this setting, use the command:

# ipadm set-prop -p _forward_directed_broadcasts=0 ip

3.6 Disable Response to ICMP Timestamp Requests (Scored)


Level 1

Description:

This setting controls whether Solaris will respond to ICMP timestamp requests.

Rationale:

Reduce attack surface by restricting this vector used for host discovery.

Audit:


# ipadm show-prop -p _respond_to_timestamp -co current ip

0

# ipadm show-prop -p _respond_to_timestamp -co persistent ip

0

Remediation:


# ipadm set-prop -p _respond_to_timestamp=0 ip

References:

1. http://capec.mitre.org/data/definitions/295.html

http://capec.mitre.org/data/definitions/295.html

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3.7 Disable Response to ICMP Broadcast Timestamp Requests (Scored)


Level 1

Description:

This setting controls whether Solaris will respond to ICMP broadcast timestamp requests.

Rationale:

Reduce attack surface by restricting this vector used for host discovery and to prevent denial of service attacks.

Audit:


# ipadm show-prop -p _respond_to_timestamp_broadcast \

-co current ip

0

# ipadm show-prop -p _respond_to_timestamp_broadcast \

-co persistent ip

0

Remediation:


# ipadm set-prop -p _respond_to_timestamp_broadcast=0 ip

References:

1. http://capec.mitre.org/data/definitions/295.html

3.8 Disable Response to ICMP Broadcast Netmask Requests (Scored)


Level 1

Description:

This setting controls whether Solaris will respond to ICMP broadcast netmask requests.

Rationale:

http://capec.mitre.org/data/definitions/295.html

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Reduce attack surface by restricting this vector used for host and network discovery and to prevent denial of service attacks.

Audit:


# ipadm show-prop -p _respond_to_address_mask_broadcast \

-co current ip

0

# ipadm show-prop -p _respond_to_address_mask_broadcast \

-co persistent ip

0

Remediation:


# ipadm set-prop -p _respond_to_address_mask_broadcast=0 ip

3.9 Disable Response to Broadcast ICMPv4 Echo Request (Scored)


Level 1

Description:

This setting controls whether Solaris responds to broadcast ICMPv4 echo requests.

Rationale:


Audit:


# ipadm show-prop -p _respond_to_echo_broadcast \

-co current ip

0

# ipadm show-prop -p _respond_to_echo_broadcast \

-co persistent ip

0

Remediation:

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# ipadm set-prop -p _respond_to_echo_broadcast=0 ip

3.10 Disable Response to Multicast Echo Request (Scored)


Level 1

Description:

These settings control whether Solaris responds to multicast IPv4 and IPv6 echo requests.

Rationale:


Audit:


# ipadm show-prop -p _respond_to_echo_multicast \

-co current ipv4

0

# ipadm show-prop -p _respond_to_echo_multicast \

-co persistent ipv4

0


# ipadm show-prop -p _respond_to_echo_multicast -co current ipv6

0

# ipadm show-prop -p _respond_to_echo_multicast -co persistent ipv6

0

Remediation:


# ipadm set-prop -p _respond_to_echo_multicast=0 ipv4


# ipadm set-prop -p _respond_to_echo_multicast=0 ipv6

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3.11 Ignore ICMP Redirect Messages (Scored)


Level 1

Description:

These settings control whether Solaris will ignore ICMP redirect messages.

Rationale:

IP redirects should not be necessary in a well-designed and maintained network. Set to a value of 1 if there is a high risk for a DoS attack. Otherwise, the default value of 0 is sufficient.

Audit:


# ipadm show-prop -p _ignore_redirect -co current ipv4

1

# ipadm show-prop -p _ignore_redirect -co persistent ipv4

1


# ipadm show-prop -p _ignore_redirect -co current ipv6

1

# ipadm show-prop -p _ignore_redirect -co persistent ipv6

1

Remediation:


# ipadm set-prop -p _ignore_redirect=1 ipv4


# ipadm set-prop -p _ignore_redirect=1 ipv6

3.12 Set Strict Multihoming (Scored)


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Level 1

Description:

These settings control whether a packet arriving on a non-forwarding interface can be accepted for an IP address that is not explicitly configured on that interface.

Rationale:

Enable this setting for systems that have interfaces that cross strict networking domains (for example, a firewall or a VPN node).

Audit:


# ipadm show-prop -p _strict_dst_multihoming -co current ipv4

1

# ipadm show-prop -p _strict_dst_multihoming -co persistent ipv4

1


# ipadm show-prop -p _strict_dst_multihoming -co current ipv6

1

# ipadm show-prop -p _strict_dst_multihoming -co persistent ipv6

1

Remediation:


# ipadm set-prop -p _strict_dst_multihoming=1 ipv4


# ipadm set-prop -p _strict_dst_multihoming=1 ipv6

3.13 Disable ICMP Redirect Messages (Scored)


Level 1

Description:

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These setting controls whether Solaris sends ICMPv4 and ICMPv6 redirect messages.

Rationale:

A malicious user can exploit the ability of the system to send ICMP redirects by continually sending packets to the system, forcing the system to respond with ICMP redirect messages, resulting in an adverse impact on the CPU performance of the system.

Audit:


# ipadm show-prop -p _send_redirects -co current ipv4

0

# ipadm show-prop -p _send_redirects -co persistent ipv4

0


# ipadm show-prop -p _send_redirects -co current ipv6

0

# ipadm show-prop -p _send_redirects -co persistent ipv6

0

Remediation:


# ipadm set-prop -p _send_redirects=0 ipv4


# ipadm set-prop -p _send_redirects=0 ipv6

3.14 Disable TCP Reverse IP Source Routing (Scored)


Level 1

Description:

This setting controls whether TCP reverses the IP source routing option for incoming connections.

Rationale:

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If IP source routing is needed for diagnostic purposes, enable it. Otherwise disable it.

Audit:


# ipadm show-prop -p _rev_src_routes -co current tcp

0

# ipadm show-prop -p _rev_src_routes -co persistent tcp

0

Remediation:


# ipadm set-prop -p _rev_src_routes=0 tcp

3.15 Set Maximum Number of Half-open TCP Connections (Scored)


Level 1

Description:

This setting controls how many half-open connections can exist for a TCP port.

Rationale:

It is necessary to control the number of completed connections to the system to provide some protection against Denial of Service attacks. Note that the value of 4096 is a minimum to establish a good security posture for this setting. In environments where connections numbers are high, such as a busy webserver, this value may need to be increased.

Audit:


# ipadm show-prop -p _conn_req_max_q0 -co current tcp

4096

# ipadm show-prop -p _conn_req_max_q0 -co persistent tcp

4096

Remediation:


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# ipadm set-prop -p _conn_req_max_q0=4096 tcp

3.16 Set Maximum Number of Incoming Connections (Scored)


Level 1

Description:

This setting controls the maximum number of incoming connections that can be accepted on a TCP port.

Rationale:

Note that the value of 1024 is a minimum to establish a good security posture for this setting. In environments where connections numbers are high, such as a busy webserver, this value may need to be increased.

Audit:


# ipadm show-prop -p _conn_req_max_q -co current tcp

1024

# ipadm show-prop -p _conn_req_max_q -co persistent tcp

1024

Remediation:


# ipadm set-prop -p _conn_req_max_q=1024 tcp

3.17 Disable Network Routing (Scored)


Level 1

Description:

The network routing daemon, in.routed, manages network routing tables. If enabled, it periodically supplies copies of the system's routing tables to any directly connected hosts and networks and picks up routes supplied to it from other networks and hosts.

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Rationale:

Routing Internet Protocol (RIP) is a legacy protocol with a number of security weaknesses including a lack of authentication, zoning, pruning, etc.

Audit:

To verify this setting for IPv4, use the command:

# routeadm -p |\

egrep "^ipv4-routing |^ipv4-forwarding " |\

awk '{printf("%s %s\n", $1, $NF); }'

ipv4-routing current=disabled

ipv4-forwarding current=disabled

To verify this setting is persistent between reboots for IPv4, use the command:

# routeadm -p |\


awk '{printf("%s %s\n", $1, $2); }'

ipv4-routing persistent=disabled

ipv4-forwarding persistent=disabled

To verify this setting for IPv6, use the command:

# routeadm -p |\


awk '{printf("%s %s\n", $1, $NF); }'

ipv6-routing current=disabled

ipv6-forwarding current=disabled

To verify this setting is persistent between reboots for IPv6, use the command:

# routeadm -p |\


awk '{printf("%s %s\n", $1, $2); }'

ipv6-routing persistent=disabled

ipv6-forwarding persistent=disabled

Remediation:

To enforce this setting and disable IPv4 routing, use the command:

# routeadm -d ipv4-forwarding -d ipv4-routing

To enforce this setting and disable IPv6 routing, use the command:

# routeadm -d ipv6-forwarding -d ipv6-routing

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To apply these changes to the running system, use the command:

# routeadm -u

4 Auditing and Logging

With the release of the Solaris 11 OS, the Solaris Audit service is enabled by default. As a result, recommendations where audit and log information was typically configured and sent to the system log (syslog) facility have been modified to use the Solaris Audit service instead. Note that for sites that still require such information to be delivered over syslog, the Solaris Audit facility can be configured to deliver audit records to that service as well.

Because it is often necessary to correlate log information from many different systems (particularly after a security incident), it is recommended that the time be synchronized among systems and devices connected to the local network. The standard Internet protocol for time synchronization is the Network Time Protocol (NTP), which is supported by most network-ready devices including Oracle Solaris 11. More information on NTP can be found at http://www.ntp.org.

4.1 Create CIS Audit Class (Scored)


Level 1

Description:

To group a set of related audit events, the Solaris Audit service provides the ability for sites to define their own audit classes that contain just those events that the site wants to audit.

Rationale:

To simplify administration, a CIS specific audit class should be created.

Audit:

Perform the following to verify that the result is as recommended:

# grep ":CIS Solaris Benchmark" /etc/security/audit_class

0x0100000000000000:cis:CIS Solaris Benchmark

Remediation:

To create the CIS audit class, edit the /etc/security/audit_class file and add the following entry before the last line of the file:

http://www.ntp.org/

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0x0100000000000000:cis:CIS Solaris Benchmark

4.2 Enable Auditing of Incoming Network Connections (Scored)


Level 1

Description:

The Solaris Audit service can be configured to record incoming network connections to any listening service running on the system.

Rationale:

This recommendation will provide an audit trail that contains information related to incoming network connections. While this functionality can be enabled using service-specific mechanisms, using the Solaris Audit service provides a more centralized and complete window into incoming network activity.

Audit:


# grep "cis" /etc/security/audit_event | awk -F: '{ print $2 }'

[…]

AUE_ACCEPT

AUE_CONNECT

AUE_SOCKACCEPT

AUE_SOCKCONNECT

AUE_inetd_connect

[…]

Remediation:

To enforce this setting, edit the /etc/security/audit_event file and add the cis audit class to the following audit events:

AUE_ACCEPT

AUE_CONNECT

AUE_SOCKACCEPT

AUE_SOCKCONNECT

AUE_inetd_connect

4.3 Enable Auditing of File Metadata Modification Events (Scored)


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Level 1

Description:

The Solaris Audit service can be configured to record file metadata modification events for every process running on the system. This will allow the auditing service to determine when file ownership, permissions and related information is changed.

Rationale:

This recommendation will provide an audit trail that contains information related to changes of file metadata. The Solaris Audit service is used to provide a more centralized and complete window into activities such as these.

Audit:



[…]

AUE_CHMOD

AUE_CHOWN

AUE_FCHOWN

AUE_FCHMOD

AUE_LCHOWN

AUE_ACLSET

AUE_FACLSET

[…]

The output of this command may include additional audit event names that had previously been assigned to the cis audit class.

Remediation:


AUE_CHMOD

AUE_CHOWN

AUE_FCHOWN

AUE_FCHMOD

AUE_LCHOWN

AUE_ACLSET

AUE_FACLSET

4.4 Enable Auditing of Process and Privilege Events (Scored)


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Level 1

Description:

The Solaris Audit service can be configured to record the use of privileges by processes running on the system. This will capture events such as the setting of UID and GID values, setting of privileges, as well as the use of functionality such as chroot(2).

Rationale:

This recommendation will provide an audit trail that contains information related to the use of privileges by processes running on the system. The Solaris Audit service is used to provide a more centralized and complete window into activities such as these.

Audit:



[…]

AUE_CHROOT

AUE_SETREUID

AUE_SETREGID

AUE_FCHROOT

AUE_PFEXEC

AUE_SETUID

AUE_NICE

AUE_SETGID

AUE_PRIOCNTLSYS

AUE_SETEGID

AUE_SETEUID

AUE_SETPPRIV

AUE_SETSID

AUE_SETPGID

[…]

The output of this command may include additional audit event names that had previously been assigned to the cis audit class.

Remediation:


AUE_CHROOT

AUE_SETREUID

AUE_SETREGID

AUE_FCHROOT

AUE_PFEXEC

AUE_SETUID

AUE_NICE

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AUE_SETGID

AUE_PRIOCNTLSYS

AUE_SETEGID

AUE_SETEUID

AUE_SETPPRIV

AUE_SETSID

AUE_SETPGID

4.5 Configure Solaris Auditing (Scored)


Level 1

Description:

Solaris auditing service keeps a record of how a system is being used. Solaris auditing can be configured to record different classes of events based upon site policy. This recommendation will set and verify a consensus-developed auditing policy. That said, all organizations are encouraged to tailor this policy based upon their specific needs. For more information on the Solaris auditing service including how to filter and view events, see the Oracle Solaris product documentation.

The "cis" class is a "custom class" that CIS recommends creating that includes specifically those events that are of interest (defined in the sections above). In addition to those events, this recommendation also includes auditing of login and logout (lo) events, administrative (ad) events, file transfer (ft) events, and command execution (ex) events.

This recommendation also configures the Solaris auditing service to capture and report command line arguments (for command execution events) and the zone name in which a command was executed (for global and non-global zones). Further, this recommendation sets a disk utilization threshold of 1%. If this threshold is crossed (for the volume that includes /var/audit), then a warning e-mail will be sent to advise the system administrators that audit events may be lost if the disk becomes full. Finally, this recommendation will also ensure that new audit trails are created at the start of each new day (to help keep the size of the files small to facilitate analysis).

Rationale:

The consensus settings described in this section are an effort to log interesting system events without consuming excessive amounts of resources logging significant but usually uninteresting system calls.

Audit:

Perform the following to determine if the system is configured as recommended:

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# auditconfig -getcond

audit condition = auditing

# auditconfig -getpolicy

configured audit policies = argv,cnt,zonename

active audit policies = argv,cnt,zonename

# auditconfig -getflags

active user default audit flags =

cis,ex,aa,ua,as,ss,lo,ft(0x1000000800f1080,0x1000000800f1080)

configured user default audit flags =

cis,ex,aa,ua,as,ss,lo,ft(0x1000000800f1080,0x1000000800f1080)

# auditconfig -getnaflags

active non-attributable audit flags = lo(0x1000,0x1000)

configured non-attributable audit flags = lo(0x1000,0x1000)

# auditconfig -getplugin audit_binfile

Plugin: audit_binfile (active)

Attributes: p_dir=/var/audit;p_fsize=0;p_minfree=1;

# userattr audit_flags root

lo,ad,ft,ex,cis:no

# ls -l /var/audit/*.not_terminated.*

[verify that the file size is not zero and is growing as events are audited]

Remediation:


# auditconfig -conf

# auditconfig -setflags lo,ad,ft,ex,cis

# auditconfig -setnaflags lo

# auditconfig -setpolicy cnt,argv,zonename

# auditconfig -setplugin audit_binfile active p_minfree=1

# audit -s

# rolemod -K audit_flags=lo,ad,ft,ex,cis:no root

# EDITOR=ed crontab -e root << END_CRON

$

a

0 * * * * /usr/sbin/audit -n

.

w

q

END_CRON

# chown root:root /var/audit

# chmod 750 /var/audit

5 File/Directory Permissions/Access

File and directory permission control is one of the greatest challenges of secure system administration. This section provides guidance on how to secure system files and directories and set secure defaults for users. Guidance for monitoring user and system files on an on-going basis is provided in the System Maintenance section of this document.

5.1 Default Service File Creation Mask (Scored)


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Level 1

Description:

The default system file creation mask applies to processes that are started by init - including most system services. To ensure that files are not created with write access to anyone other than their owner, the default file creation mask should be set to 022. Some sites with more stringent security requirements may prefer to set this value to 077 to eliminate all permissions for group and world. Note that changing this value from the Solaris default of 022 may negatively impact services that may not be able to operate with a stricter setting.

Rationale:

The default file creation mask should be set to 022 to avoid unnecessarily giving files write access to group or world.

Audit:


# svcprop -p umask/umask svc:/system/environment:init

022

Remediation:

Perform the following to implement the recommended state:

# svccfg -s svc:/system/environment:init \

setprop umask/umask = astring: "022"

5.2 Set Sticky Bit on World Writable Directories (Not Scored)


Level 1

Description:

When the so-called sticky bit (set with chmod +t) is set on a directory, then only the owner of a file may remove that file from the directory (as opposed to the usual behavior where anybody with write access to that directory may remove the file).

Rationale:

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Files in directories that have had the 'sticky bit' set, can only be deleted by users that have both write permissions for the directory in which the file resides, as well as ownership of the file or directory, or has sufficient privilege. As this prevents users from overwriting each other's files, whether it be accidental or malicious, it is generally appropriate for most world-writable directories (e.g., /tmp). However, consult appropriate vendor documentation before blindly applying the sticky bit to any world writable directories found, in order to avoid breaking any application dependencies on a given directory.

Audit:


# find / $ -fstype nfs -o -fstype cachefs -o -fstype autofs \

-o -fstype ctfs -o -fstype mntfs -o -fstype objfs \

-o -fstype proc $ -prune -o -type d $ -perm -0002 \

-a ! -perm -1000 $ -ls

Remediation:

To set the sticky bit on a directory, run the following command:

# chmod +t [directory name]

6 System Access, Authentication, and Authorization

The actions described in this section are just a few measures that can be taken at a system level to control access to the system and its services. It is strongly advised that organizations have a process in place to document, authorize, and validate access privileges and to revoke authorizations when they are no longer required.

6.1 Disable login: Services on Serial Ports (Scored)


Level 1

Description:

The svccfg command provides service administration for the lower level of the Service Access Facility hierarchy and can be used to disable the ability to login on a particular port.

Rationale:

Login services should not be enabled on any serial ports that are not strictly required to support the mission of the system. This action can be safely performed even when console access is provided using a serial port.

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Audit:


# svcs -Ho state svc:/system/console-login:terma

disabled

# svcs -Ho state svc:/system/console-login:termb

disabled

Remediation:


# svcadm disable svc:/system/console-login:terma

# svcadm disable svc:/system/console-login:termb

6.2 Disable "nobody" Access for RPC Encryption Key Storage Service (Scored)


Level 1

Description:

This action listed prevents keyserv from using default keys for the nobody user, effectively stopping the nobody user from accessing information via Secure RPC.

Rationale:

If login by the user nobody is allowed for secure RPC, there is an increased risk of system compromise. If keyserv holds a private key for the nobody user, it will be used by key_encryptsession to compute a magic phrase which can be easily recovered by a malicious user.

Audit:


# grep "^ENABLE_NOBODY_KEYS=" /etc/default/keyserv

ENABLE NOBODY KEYS=NO

Remediation:


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# cd /etc/default

# awk '/ENABLE_NOBODY_KEYS=/ \

{ $1 = "ENABLE_NOBODY_KEYS=NO" }

{ print }' keyserv > keyserv.CIS

# mv keyserv.CIS keyserv

6.3 Disable X11 Forwarding for SSH (Scored)


Level 1

Description:

The 'X11 Forwarding' parameter defined within the /etc/ssh/sshd_config file specifies whether or not X11 Forwarding via SSH is enabled on the server: The Secure Shell service provides an encrypted 'tunnel' for the data traffic passing through it. While commonly used to substitute for clear-text, CLI-based remote connections such as telnet, Secure Shell can be used to forward an 'X Window' session through the encrypted tunnel, allowing the remote user to have a GUI interface.

Rationale:

As enabling X11Forwarding on the host can permit a malicious user to secretly open another X11 connection to another remote client during the session and perform unobtrusive activities such as keystroke monitoring, if the X11 services are not required for the system's intended function, it should be disabled or restricted as appropriate to the user's needs.

Audit:


# grep "^X11Forwarding" /etc/ssh/sshd_config

X11Forwarding no

Remediation:


# awk '/^X11Forwarding / { $2 = "no" } \

{ print }' /etc/ssh/sshd_config > /etc/ssh/sshd_config.CIS

# mv /etc/ssh/sshd_config.CIS /etc/ssh/sshd_config

# svcadm restart svc:/network/ssh

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6.4 Limit Consecutive Login Attempts for SSH (Scored)


Level 1

Description:

The 'MaxAuthTries' parameter in the /etc/ssh/sshd_config file specifies the maximum number of authentication attempts permitted per connection. By restricting the number of failed authentication attempts before the server terminates the connection, malicious users are blocked from gaining access to the host by using repetitive brute-force login exploits.

Rationale:

By setting the authentication login limit to a low value this will disconnect the attacker and force a reconnect, which severely limits the speed of such brute force attacks.

Audit:


# grep "^MaxAuthTries" /etc/ssh/sshd_config

MaxAuthTries 3

Remediation:


# awk '/^MaxAuthTries/ { $2 = "3" } \




6.5 Disable Rhost-based Authentication for SSH (Scored)


Level 1

Description:

The IgnoreRhosts parameter specifies that existing .rhosts and .shosts files, which may apply to application rather than user logins, will not be used in RhostsRSAAuthentication or HostbasedAuthentication.

Rationale:

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Setting this parameter forces users to enter a password when authenticating with SSH.

Audit:


# grep "^IgnoreRhosts" /etc/ssh/sshd_config

IgnoreRhosts yes

If the IgnoreRhosts line does not exist in the file, the default setting of Yes is automatically applied.

Remediation:


# awk '/^IgnoreRhosts/ { $2 = "yes" } \




This action will only set the IgnoreRhosts line if it already exists in the file to ensure that it is set to the proper value. If the IgnoreRhosts line does not exist in the file, the default setting of Yes is automatically used, so no additional changes are needed.

6.6 Disable root login for SSH (Scored)


Level 1

Description:

The PermitRootLogin value (in /etc/ssh/sshd_config) allows for direct root login by a remote user/application to resources on the local host.

Rationale:

By default, it is not possible for the root account to log directly into the system console because the account is configured as a role. This setting therefore does not significantly alter the security posture of the system unless the root account is changed from this default and configured to be a normal user.

Audit:


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# grep "^PermitRootLogin" /etc/ssh/sshd_config

PermitRootLogin no

Remediation:


# awk '/^PermitRootLogin/ { $2 = "no" } \




6.7 Blocking Authentication Using Empty/Null Passwords for SSH (Scored)


Level 1

Description:

The PermitEmptyPasswords value allows for direct login through SSH without a password by a remote user/application to resources on the local host in the same way a standard remote login would.

Rationale:

Permitting login without a password is inherently risky.

Audit:


# grep "^PermitEmptyPasswords" /etc/ssh/sshd_config

PermitEmptyPasswords no

Remediation:


# awk '/^PermitEmptyPasswords/ { $2 = "no" } \




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6.8 Disable Host-based Authentication for Login-based Services (Scored)


Level 1

Description:

The .rhosts files are used for automatic login to remote hosts and contain username and hostname combinations. The .rhosts files are unencrypted (usually group- or world-readable) and present a serious risk in that a malicious user could use the information within to gain access to a remote host with the privileges of the original application or user.

Rationale:

The use of .rhosts authentication is an old and insecure protocol and can be replaced with public-key authentication using Secure Shell. As automatic authentication settings in the .rhosts files can provide a malicious user with sensitive system credentials, the use of .rhosts files should be disabled. It should be noted that by default the Solaris services that use this file, including rsh and rlogin, are disabled by default.

Audit:


# grep "^#" /etc/pam.conf | grep "pam_rhosts_auth"

#rlogin auth sufficient pam_rhosts_auth.so.1

#rsh auth sufficient pam_rhosts_auth.so.1

Remediation:


# cd /etc

# cp pam.conf pam.conf.pre-CIS

# sed -e 's/^.*pam_rhosts_auth/#&/' < /etc/pam.conf \

> pam.conf.CIS

# mv pam.conf.CIS pam.conf

6.9 Restrict FTP Use (Scored)


Level 1

Description:

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If FTP is permitted to be used on the system, the file /etc/ftpd/ftpusers is used to specify a list of users who are not allowed to access the system via FTP.

Rationale:

FTP is an old and insecure protocol that transfers files and credentials in clear text and can be replaced by using sftp. However, if FTP is permitted for use in your environment, it is important to ensure that the default "system" accounts are not permitted to transfer files via FTP, especially the root role. Consider also adding the names of other privileged or shared accounts that may exist on your system such as user oracle and the account which your Web server process runs under. It should be reminded that the Solaris FTP service is disabled by default.

Audit:


# for user in `logins -s | awk '{ print $1 }'` \

aiuser noaccess nobody nobody4; do

grep -w "${user}" /etc/ftpd/ftpusers >/dev/null 2>&1

if [ $? != 0 ]; then

echo "User '${user}' not in /etc/ftpd/ftpusers."

fi

done

(No output should be returned.)

Remediation:


# cd /etc/ftpd

# for user in `logins -s | awk '{ print $1 }'` \

aiuser noaccess nobody nobody4; do

$(echo $user >> ftpusers)

done

# sort -u ftpusers > ftpusers.CIS

# mv ftpusers.CIS ftpusers

If your site policy states that users have to be authorized to use FTP, consider placing all users in the /etc/ftpd/ftpusers file and then explicitly removing those who are permitted to use the service. To accomplish this, use the command:

# getent passwd | cut -f1 -d":" > /etc/ftpd/ftpusers

This prohibits any user on the system from using ftp unless they are explicitly removed from the file. Note that this file will need to be updated as users are added to or removed from the system.

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6.10 Set Delay between Failed Login Attempts to 4 (Scored)


Level 1

Description:

The SLEEPTIME variable in the /etc/default/login file controls the number of seconds to wait before printing the "login incorrect" message when a bad password is provided.

Rationale:

As an immediate return of an error message, coupled with the capability to try again may facilitate automatic and rapid-fire brute-force password attacks by a malicious user, this delay time should be set as appropriate to the needs of the user.

Audit:


# grep "^SLEEPTIME=" /etc/default/login

SLEEPTIME=4

Remediation:


# cd /etc/default

# awk '/SLEEPTIME=/ { $1 = "SLEEPTIME=4" }

{ print }' login > login.CIS

# mv login.CIS login

6.11 Remove Autologin Capabilities from the GNOME desktop (Scored)


Level 1

Description:

The GNOME Display Manager is used for login session management. See the manual page gdm(1) for more information. By default, GNOME automatic login is defined in pam.conf(4) to allow users to access the system without a password.

Rationale:

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As automatic logins are a known security risk for other than "kiosk" types of systems, GNOME automatic login should be disabled in pam.conf(4).

Audit:


# grep "^#gdm-autologin" /etc/pam.conf

#gdm-autologin auth required pam_unix_cred.so.1

#gdm-autologin auth sufficient pam_allow.so.1

#gdm-autologin account sufficient pam_allow.so.1

Remediation:


# cd /etc

# awk '/^gdm-autologin/ { $1="#gdm-autologin" } { print }' \

/etc/pam.conf > /etc/pam.conf.CIS

# mv pam.conf.CIS pam.conf

6.12 Set Default Screen Lock for GNOME Users (Scored)


Level 1

Description:

The timeout parameter dictates the invocation of a password-protected screen saver after a specified time of keyboard and mouse inactivity, specific to the xscreensaver application used in the GNOME windowing environment.

Rationale:

As a screensaver timeout provides protection for a desktop that has not been locked by the user upon his/her departure, to help prevent session hijacking, this value should be set as appropriate to the needs of the user.

Audit:


# cd /usr/share/X11/app-defaults

# grep "^\*timeout:" XScreenSaver

*timeout: 0:10:00

# grep "^\*lockTimeout:" XScreenSaver

*lockTimeout: 0:00:00

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# grep "^\*lock:" XScreenSaver

*lock: True

Remediation:


# cd /usr/share/X11/app-defaults

# cp XScreenSaver XScreenSaver.orig

# awk '/^\*timeout:/ { $2 = "0:10:00" }

/^\*lockTimeout:/ { $2 = "0:00:00" }

/^\*lock:/ { $2 = "True" }

{ print }' xScreenSaver > xScreenSaver.CIS

# mv xScreenSaver.CIS xScreenSaver

6.13 Restrict at/cron to Authorized Users (Scored)


Level 1

Description:

The cron.allow and at.allow files contain a list of users who are allowed to run the crontab and at commands to submit jobs to be run at scheduled intervals.

Rationale:

On many systems, only the system administrator needs the ability to schedule jobs. Even though a given user is not listed in cron.allow, cron jobs can still be run as that user. The cron.allow file only controls administrative access to the crontab command for scheduling and modifying cron jobs. Much more effective access controls for the cron system can be obtained by using Role-Based Access Controls (RBAC).

Audit:


# ls /etc/cron.d/cron.deny

/etc/cron.d/cron.deny: No such file or directory

# ls /etc/cron.d/at.deny

/etc/cron.d/at.deny: No such file or directory

# cat /etc/cron.d/cron.allow

root

# wc -l /etc/cron.d/at.allow | awk '{ print $1 }'

0

Remediation:


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# cd /etc/cron.d

# mv cron.deny cron.deny.cis

# mv at.deny at.deny.cis

# echo root > cron.allow

# cp /dev/null at.allow

# chown root:root cron.allow at.allow

# chmod 400 cron.allow at.allow

6.14 Restrict root Login to System Console (Scored)


Level 1

Description:

Privileged access to the system via root must be accountable to a particular user.

Rationale:

Use an authorized mechanism such as RBAC and the su command to provide administrative access to unprivileged accounts. These mechanisms provide an audit trail in the event of problems.

Audit:


# grep "^CONSOLE=/dev/console" /etc/default/login

CONSOLE=/dev/console

Remediation:


# cd /etc/default

# awk '/CONSOLE=/ { print "CONSOLE=/dev/console"; next }; \



6.15 Set Retry Limit for Account Lockout (Scored)


Level 1

Description:

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The RETRIES parameter is the number of failed login attempts a user is allowed before being disconnected from the system and forced to reconnect. When LOCK_AFTER_RETRIES is set in /etc/security/policy.conf, then the user's account is locked after this many failed retries (the account can only be unlocked by the administrator using the command: passwd -u <username>). The account lockout threshold (RETRIES parameter) restricts the number of failed login attempts allowed before requiring the offending account be locked. The lockout requirement will help block malicious users from gaining access to the host via automated, repetitive brute-force login exploits--trying different passwords until one fits a user name.

Rationale:

Setting the failed login limit to an appropriate value locks the user account, which will severely limit the speed of such attacks, making it much more likely that the attacker's pattern will be noticed and the offending source address and/or port blocked, so this should be set according to the needs of the user.

Audit:


# grep "^RETRIES=" /etc/default/login

RETRIES=3

# grep "^LOCK_AFTER_RETRIES=" /etc/security/policy.conf

LOCK_AFTER_RETRIES=YES

# userattr lock_after_retries [username]

(Output should be "no" for any accounts that are exempt from this policy including

"root".)

Remediation:


# cd /etc/default

# awk '/RETRIES=/ { $1 = "RETRIES=3" }

{ print }' login >login.CIS


# cd /etc/security

# awk '/LOCK_AFTER_RETRIES=/ \

{ $1 = "LOCK_AFTER_RETRIES=YES" }

{ print }' policy.conf > policy.conf.CIS

# mv policy.conf.CIS policy.conf

# svcadm restart svc:/system/name-service/cache

Be careful when enabling these settings as they can create a denial-of-service situation for legitimate users and applications. Account lockout can be disabled for specific users via the usermod command. For example, the following command disables account lock specifically for the oracle account:

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# usermod -K lock_after_retries=no oracle

Note: The root role is configured in this manner by default to prevent accidental lock out.

6.16 Set EEPROM Security Mode and Log Failed Access (SPARC) (Not Scored)


Level 1

Description:

Oracle SPARC systems support the use of a EEPROM password for the console.

Rationale:

Setting the EEPROM password helps prevent attackers who gain physical access to the system console from booting from an external device (such as a CD-ROM or floppy).

Audit:


# eeprom security-mode | awk -F= '{ print $2 }'

[command|full|none]

# eeprom security-#badlogins | awk -F= '{ print $2 }'

0

If a password has been set, the command will return command or full. If a password has not been set, the command will return none.

Remediation:


# eeprom security-mode=command

# eeprom security-#badlogins=0

After entering the last command above, the administrator will be prompted for a password. This password will be required to authorize any future command issued at boot-level on the system (the ok or > prompt) except for the normal multi-user boot command (i.e., the system will be able to reboot unattended).

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Write down the password and store it in a sealed envelope in a secure location (note that locked desk drawers are typically not secure). If the password is lost or forgotten, simply log into the system and run the command:

# eeprom security-mode=none

This will erase the forgotten password. If the password is lost or forgotten and this action cannot be completed, then the EEPROM must be replaced to gain access to the system. To set a new password, run the command:

# eeprom security-mode=command

6.17 Secure the GRUB Menu (Intel) (Scored)


Level 1

Description:

GRUB is a boot loader for x64 based systems that permits loading an OS image from any location. Oracle x64 systems support the use of a GRUB Menu password for the console.

Rationale:

The flexibility that GRUB provides creates a security risk if its configuration is modified by an unauthorized user. The failsafe menu entry needs to be secured in the same environments that require securing the systems firmware to avoid unauthorized removable media boots. Setting the GRUB Menu password helps prevent attackers with physical access to the system console from booting off some external device (such as a CD-ROM or floppy) and subverting the security of the system. The actions described in this section will ensure you cannot get to failsafe or any of the GRUB command line options without first entering the password.

Audit:


# grep "^password --md5" /rpool/boot/grub/menu.lst

password --md5 [password string]

In addition, a manual verification of the lock commands is necessary to ensure that the appropriate boot images are protected.

Remediation:

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# /boot/grub/bin/grub

grub> md5crypt

Password: [enter desired boot loader password]

Encrypted: [enter md5 password string]

grub> [enter control-C (^C)]

The actual menu.lst file for Solaris 11 x64 is the /rpool/boot/grub/menu.lst. First, ensure the menu.lst file can only be read by the root user:

# chmod 600 /rpool/boot/grub/menu.lst

Next, add the following line to the menu.lst file above the entries added by bootadm:

password --md5 [enter md5 password string generated above]

Finally, add the keyword lock to the Solaris failsafe boot entry as in the following example (as well as to any other entries that you want to protect):

title Solaris failsafe

lock

7 User Accounts and Environment

This section provides guidance on setting up secure defaults for system and user accounts and their environment. Guidance for monitoring these settings and others that may change over time is provided in the System Maintenance section of this document.

7.1 Set Password Expiration Parameters on Active Accounts (Scored)


Level 1

Description:

The characteristics of an operating system that make 'user identification' via password a secure and workable solution is the combination of settings chosen. By requiring that a series of password-choices be security-centric, it reduces the risk of a malicious user breaking the password through dictionary/brute force attacks or fortuitous guessing based upon 'social engineering.' A basic password security strategy is requiring a new password to be chosen every 45-90 days, so that repeated attempts to gain entry by brute-force tactics will fail when a new password is chosen, which requires starting over again to break the new password.

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Rationale:

The commands for this item set all active accounts (except the root account) to force password changes every 91 days (13 weeks), and then prevent password changes for seven days (one week), thereafter. Users will begin receiving warnings 28 days (4 weeks) before their password expires. Sites also have the option of expiring idle accounts after a certain number of days (see the on-line manual page for the usermod command, particularly the -f option).

Audit:


# logins -ox |\

awk -F: '( $1 != "root" && $8 != "LK" && $8 != "NL" && \

( $10 != "7" || $11 != "91" || $12 != "28" )) { print }'


# grep "WEEKS=" /etc/default/passwd | sort -u

MAXWEEKS=13

MINWEEKS=1

WARNWEEKS=4

Remediation:


# logins -ox |\

awk -F: '($1 == "root" || $8 == "LK" || $8 == "NL") \

{ next } ; \

{ $cmd = "passwd" } ;\

($11 91) { $cmd = $cmd " -x 91" } \

($10 < 7) { $cmd = $cmd " -n 7" } \

($12 < 28) { $cmd = $cmd " -w 28" } \

($cmd != "passwd") { print $cmd " " $1 }' \

> /etc/CISupd_accounts

# /sbin/sh /etc/CISupd_accounts

# rm -f /etc/CISupd_accounts

# cd /etc/default

# grep -v WEEKS passwd > passwd.CIS

# cat <<EODefaults >> passwd.CIS

MAXWEEKS=13

MINWEEKS=1

WARNWEEKS=4

EODefaults

# mv passwd.CIS passwd

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7.2 Set Strong Password Creation Policies (Scored)


Level 1

Description:

The variables in the /etc/default/passwd file indicate various strategies for creating differences required between an old and a new password. As requiring users to select a specific numbers of differences between the characters in the existing password and the new one can strengthen the password by increasing the symbol-set space, to further increase the difficulty of breaking any password by brute-force attacks, these values should be set as appropriate to the needs of the user.

Rationale:

Administrators may wish to add site-specific dictionaries to the DICTIONLIST parameter.

Warning: Sites often have differing opinions on the optimal value of the HISTORY parameter (how many previous passwords to remember per user in order to prevent re-use). The values specified here are in compliance with NSA/DISA requirements. If this is too restrictive for your site, you may wish to set a HISTORY value of 4 and a MAXREPEATS of 2. Consult your local security rules for guidance.

Audit:


# grep "^PASSLENGTH=" /etc/default/passwd

PASSLENGTH=8

# grep "^NAMECHECK=" /etc/default/passwd

NAMECHECK=YES

# grep "^HISTORY=" /etc/default/passwd

HISTORY=10

# grep "^MINDIFF=" /etc/default/passwd

MINDIFF=3

# grep "^MINALPHA=" /etc/default/passwd

MINALPHA=2

# grep "^MINUPPER=" /etc/default/passwd

MINUPPER=1

# grep "^MINLOWER=1" /etc/default/passwd

MINLOWER=1

# grep "^MINNONALPHA=1" /etc/default/passwd

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MINNONALPHA=1

# grep "^MAXREPEATS=0" /etc/default/passwd

MAXREPEATS=0

# grep "^WHITESPACE=YES" /etc/default/passwd

WHITESPACE=YES

# grep "^DICTIONDBDIR=/var/passwd" /etc/default/passwd

DICTIONDBDIR=/var/passwd

# grep "^DICTIONLIST=/usr/share/lib/dict/words" \

/etc/default/passwd

DICTIONLIST=/usr/share/lib/dict/words

Remediation:


# cd /etc/default

# awk '/PASSLENGTH=/ { $1 = "PASSLENGTH=8" };

/NAMECHECK=/ { $1 = "NAMECHECK=YES" };

/HISTORY=/ { $1 = "HISTORY=10" };

/MINDIFF=/ { $1 = "MINDIFF=3" };

/MINALPHA=/ { $1 = "MINALPHA=2" };

/MINUPPER=/ { $1 = "MINUPPER=1" };

/MINLOWER=/ { $1 = "MINLOWER=1" };

/MINNONALPHA=/ { $1 = "MINNONALPHA=1" };

/MAXREPEATS=/ { $1 = "MAXREPEATS=0" };

/WHITESPACE=/ { $1 = "WHITESPACE=YES" };

/DICTIONDBDIR=/ { $1 = "DICTIONDBDIR=/var/passwd" };

/DICTIONLIST=/ \

{ $1 = "DICTIONLIST=/usr/share/lib/dict/words" };

{ print }' passwd > passwd.CIS

# mv passwd.CIS passwd

7.3 Set Default umask for users (Scored)


Level 1

Description:

The default umask(1) determines the permissions of files created by users. The user creating the file has the discretion of making their files and directories readable by others via the chmod(1) command. Users who wish to allow their files and directories to be readable by others by default may choose a different default umask by inserting the umask command into the standard shell configuration files (.profile, .cshrc, etc.) in their home directories.

Rationale:

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Setting a very secure default value for umask ensures that users make a conscious choice about their file permissions. A default umask setting of 077 causes files and directories created by users to not be readable by any other user on the system. A umask of 027 would allow files and directories readable by users in the same Unix group, while a umask of 022 would make files readable by every user on the system.

Audit:


# grep "^UMASK=" /etc/default/login

UMASK=027

Remediation:


# cd /etc/default

# awk '/#UMASK=/ { $1 = "UMASK=027" }



7.4 Set Default File Creation Mask for FTP Users (Scored)


Level 1

Description:

If FTP is permitted, set a strong, default file creation mask to apply to files created by the FTP server.

Rationale:

Many users assume that the FTP server will use their system file creation mask; generally it does not. This setting ensures that files transmitted over FTP use a strong file creation mask.

Audit:


# grep "^Umask" /etc/proftpd.conf | awk '{ print $2 }'

027

Remediation:

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# cd /etc

# if [ "`grep '^Umask' proftpd.conf`" ]; then

awk '/^Umask/ { $2 = "027" }

{ print }' proftpd.conf > proftpd.conf.CIS

mv proftpd.conf.CIS proftpd.conf

else

echo "Umask 027" >> proftpd.conf

fi

7.5 Set "mesg n" as Default for All Users (Scored)


Level 1

Description:

The "mesg n" command blocks attempts to use the write or talk commands to contact users at their terminals, but has the side effect of slightly strengthening permissions on the user's tty device.

Rationale:

Since write and talk are no longer widely used at most sites, the incremental security increase is worth the loss of functionality.

Audit:


# grep "^mesg" /etc/.login

mesg n

# grep "^mesg" /etc/profile

mesg n

Remediation:


# cd /etc

# for file in profile .login ; do

if [ "`grep mesg $file`" ]; then

awk '$1 == "mesg" { $2 = "n" }

{ print }' $file > $file.CIS

mv $file.CIS $file

else

echo mesg n >> $file

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fi

done

7.6 Lock Inactive User Accounts (Scored)


Level 1

Description:

Guidelines published by the U.S. Department of Defense specify that user accounts must be locked out after 35 days of inactivity. This number may vary based on the particular site's policy.

Rationale:

Inactive accounts pose a threat to system security since the users are not logging in to notice failed login attempts or other anomalies.

Audit:


# useradd -D | xargs -n 1 | grep inactive |\

awk -F= '{ print $2 }'

35

# logins -axo -l "[name]" | awk -F: '{ print $13 }'

35

Remediation:


# useradd -D -f 35

To set this policy on a user account, use the command(s):

# usermod -f 35 [name]

To set this policy on a role account, use the command(s):

# rolemod -f 35 [name]

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8 Warning Banners

Presenting a warning message prior to the normal user login may assist the prosecution of trespassers on the computer system. Changing some of these login banners also has the side effect of hiding OS version information and other detailed system information from attackers attempting to target specific exploits at a system.

Guidelines published by the US Department of Defense require that warning messages include at least the name of the organization that owns the system, the fact that the system is subject to monitoring and that such monitoring is in compliance with local statutes, and that use of the system implies consent to such monitoring. It is important that the organization's legal counsel review the content of all messages before any system modifications are made, as these warning messages are inherently site-specific. More information (including citations of relevant case law) can be found at http://www.justice.gov/criminal/cybercrime/

Note: The text provided in the remediation actions for these items is intended as an example ONLY. Please edit to include the specific text for your organization as approved by your legal department.

8.1 Create Warnings for Standard Login Services (Scored)


Level 1

Description:

The contents of the /etc/issue file are displayed prior to the login prompt on the system's console and serial devices and also prior to logins via telnet and Secure Shell. The contents of the /etc/motd file are generally displayed after all successful logins, regardless from where the user is logging in.

Rationale:

Warning messages inform users who are attempting to login to the system of their legal status regarding the system and must include the name of the organization that owns the system and any monitoring policies that are in place. As implementing a logon banner to deter inappropriate use and can provide a foundation for legal action against abuse, this warning content should be set as appropriate. Consult with your organization's legal counsel for the appropriate wording as the examples below are for demonstration purposes only.

Audit:

http://www.justice.gov/criminal/cybercrime/

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# cat /etc/motd

Authorized users only. All activity may be monitored and reported.

# ls -l /etc/motd

-rw-r--r-- 1 root sys 67 Dec 20 18:28 /etc/motd

# cat /etc/issue

Authorized users only. All activity may be monitored and reported.

# ls -l /etc/issue

-rw-r--r-- 1 root root 66 Dec 20 18:27 /etc/issue

Remediation:


# echo "Authorized users only. All activity may be monitored and reported." >

/etc/motd

# echo "Authorized users only. All activity may be monitored and reported." >

/etc/issue

# chown root:root /etc/issue

# chmod 644 /etc/issue

8.2 Enable a Warning Banner for the SSH Service (Scored)


Level 1

Description:

The contents of the Banner string in the /etc/ssh/sshd_config file are sent to the remote user before authentication is allowed, requiring that the user read the legal caution.

Rationale:

Audit:


# grep "^Banner" /etc/ssh/sshd_config

Banner /etc/issue

Remediation:

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# awk '/^#Banner/ { $1 = "Banner" } \




8.3 Enable a Warning Banner for the GNOME Service (Scored)


Level 1

Description:

The GNOME Display Manager is used for login session management. See the manual page gdm(1) for more information on configuration of the settings, which can be user- or group specific.

Rationale:

The remediation action for this item sets a pre-login warning message for GDM users. Additional methods can be employed to display a similar message to a user post-authentication. For more information, see the Oracle Solaris 11 Security Guidelines document.

Audit:


# cd /etc/gdm/Init

# grep "Security Message" Default

--title="Security Message" --filename=/etc/issue

Remediation:


Edit the /etc/gdm/Init/Default file to add the following content before the last line of the file.

/usr/bin/zenity --text-info --width=800 --height=300 \

--title="Security Message" --filename=/etc/issue

8.4 Enable a Warning Banner for the FTP service (Scored)


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Level 1

Description:

The action for this item sets a warning message for FTP users before they log in.

Rationale:

Warning Banners inform users who are attempting to access the system of their legal status regarding using the system. The text below is a generic sample only, so consult with your organization's legal counsel for the appropriate wording.

Audit:


# grep "DisplayConnect" /etc/proftpd.conf

DisplayConnect /etc/issue

Remediation:


# echo "DisplayConnect /etc/issue" >> /etc/proftpd.conf

# svcadm restart ftp

8.5 Check that the Banner Setting for telnet is Null (Scored)


Level 1

Description:

The BANNER variable in the file /etc/default/telnetd can be used to display text before the telnet login prompt. Traditionally, it has been used to display the OS level of the target system.

Rationale:

The warning banner provides information that can be used in reconnaissance for an attack. By default, this file is distributed with the BANNER variable set to null. It is not necessary to create a separate warning banner for telnet if a warning is set in the /etc/issue file. As telnet is an insecure protocol, it is strongly recommend that it be disabled and all remote administrative/user connections take place by Secure Shell.

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Audit:


# grep "^BANNER" /etc/default/telnetd

BANNER=

Remediation:


# cd /etc/default

# awk '/^BANNER=/ { $1 = "BANNER=" }; { print }' \

telnetd > telnetd.CIS

# mv telnetd.CIS telnetd

9 System Maintenance

No matter how securely a system has been installed and hardened, administrator and user activity over time can introduce security exposures. This section describes tasks to be performed on a regular, ongoing basis—perhaps in an automated fashion via the cron utility. The automated host-based scanning tools provided from the Center for Internet Security can be used for this purpose. These scanning tools are typically provided with this document, but are also available for free from http://www.CISecurity.org/.

Note that, unlike other sections, the items in this section specify an Audit action followed by a Remediation action, since it is necessary to determine what the current setting is before determining remediation measures, which will vary depending on the site's policy.

9.1 Check for Remote Consoles (Scored)


Level 1

Description:

The consadm command can be used to select or display alternate console devices.

Rationale:

Since the system console has special properties to handle emergency situations, it is important to ensure that the console is in a physically secure location and that unauthorized consoles have not been defined. The "consadm -p" command displays any alternate consoles that have been defined as auxiliary across reboots. If no remote consoles have been defined, there will be no output from this command.

http://www.cisecurity.org/

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Audit:


# /usr/sbin/consadm -p


Remediation:


# /usr/sbin/consadm [-d device...]

9.2 Verify System File Permissions (Not Scored)


Level 1

Description:

The pkg verify and command checks the accuracy of installed directory structures and files.

Rationale:

It is important to ensure that system files and directories are maintained with the permissions they were intended to have from the OS vendor (Oracle).

Audit:


# pkg verify

Errors may be a simple reflection of changes made earlier in this benchmark, such as alteration of the ownership of the cron process, so this result indicates that pkg verify is doing its job and detecting file changes.

Remediation:

Correct or justify any items discovered in the Audit step. Perform the following to set correct any identified package errors:

# pkg fix

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Exercise caution in running this command as it may reverse modifications implemented previously including some of those recommended by this document. Rather than use this command broadly, it is recommended that it be used more tactically to correct specific package problems when possible.

9.3 Verify System Account Default Passwords (Scored)


Level 1

Description:

There are a number of accounts provided with the Solaris OS that are used to manage applications and are not intended to provide an interactive shell. These accounts are delivered either in a locked or non-login state. Oracle does not support nor recommend changing the passwords associated with these accounts.

Rationale:

System accounts, such as bin, lpd, and sys have special purposes and privileges. By default, these accounts are configured as either locked or non-login. This status should be verified to ensure that these accounts have not accidentially or intentionally been enabled.

Audit:

Verify that each of the following accounts are locked:

# for user in aiuser dhcpserv dladm ftp gdm netadm netcfg \

noaccess nobody nobody4 openldap pkg5srv svctag unknown \

webservd xvm; do

stat=`passwd -s ${user} | awk '{ print $2 }'`

if [ "${stat}" != "LK" ]; then

echo "Account ${user} is not locked."

fi

done


Verify that each of the following accounts are non-login:

# for user in adm bin daemon lp mysql nuucp postgres smmsp \

sys upnp uucp zfssnap; do

stat=`passwd -s ${user} | awk '{ print $2 }'`

if [ "${stat}" != "NL" ]; then

echo "Account ${user} is not non-login."

fi

done


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Remediation:

To lock a single account, use the command:

# passwd -d [username]

# passwd -l [username]

To configure a single account to be non-login, use the command:

# passwd -d [username]

# passwd -N [username]

9.4 Ensure Password Fields are Not Empty (Scored)


Level 1

Description:

An account with an empty password field means that anybody may log in as that user without providing a password at all (assuming that the value PASSREQ=NO is set in /etc/default/login).

Rationale:

All accounts must have passwords, be configured as "Non-login," or be locked.

Audit:


# logins -p


Remediation:

Use the passwd -l command to lock accounts that are not permitted to execute commands . Use the passwd -N command to set accounts to be non-login.

9.5 Verify No UID 0 Accounts Exist Other than root (Scored)


Level 1

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Description:

Any account with UID 0 has superuser rights on the system.

Rationale:

This access must be limited to only the default root role and be made accessible from the system console only. Administrative access granted to an unprivileged account should use an approved mechanism such as RBAC.

Audit:


# logins -o | awk -F: '($2 == 0) { print $1 }'

root

Remediation:

Disable or delete any other 0 UID entries that are displayed; there should be only one root account. Finer granularity access control for administrative access can be obtained by using the Solaris Role-Based Access Control (RBAC) mechanism. RBAC configurations should be monitored via user_attr(4) to make sure that privileges are managed appropriately.

9.6 Ensure root PATH Integrity (Scored)


Level 1

Description:

The root user can execute any command on the system and could be tricked into executing programs if the PATH is not set correctly.

Rationale:

Including the current working directory (.) or any other writable directory in root's executable path makes it likely that an attacker can gain superuser access by forcing an administrator operating as root to execute a malcode, such as a Trojan horse program.

Audit:


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# if [ "ècho $PATH | grep :: `" != "" ]; then

echo "Empty Directory in PATH (::)"

fi

# if [ "ècho $PATH | grep :$`" != "" ]; then

echo "Trailing : in PATH"

fi

# p=ècho $PATH | sed -e 's/::/:/' -e 's/:$//' -e 's/:/ /g'`

# set -- $p

# while [ "$1" != "" ]; do

if [ "$1" = "." ]; then

echo "PATH contains ."

shift

continue

fi

if [ -d $1 ]; then

dirperm=`ls -ld $1 | cut -f1 -d" "`

if [ ècho $dirperm | cut -c6 ` != "-" ]; then

echo "Group Write permission set on directory $1"

fi

if [ ècho $dirperm | cut -c9 ` != "-" ]; then

echo "Other Write permission set on directory $1"

fi

fi

shift

done


Remediation:

Correct or justify any items discovered in the Audit step.

9.7 Check Permissions on User Home Directories (Scored)


Level 1

Description:

While the system administrator can establish secure permissions for users' home directories, the users can easily override these.

Rationale:

Group or world-writable user home directories may enable malicious users to steal or modify other users' data or to gain another user's system privileges.

Audit:


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# for dir in `logins -ox |\

awk -F: '($8 == "PS") { print $6 }'`; do

find ${dir} -type d -prune $ -perm -g+w -o \

-perm -o+r -o -perm -o+w -o -perm -o+x $ -ls

done


Remediation:

Correct or justify any items discovered in the Audit step. Determine if any user directory permissions are world-readable, writable, or executable, and work with those users to determine the best course of action in accordance with site policy.

9.8 Check Permissions on User "." (Hidden) Files (Scored)


Level 1

Description:

While the system administrator can establish secure permissions for users' "dot" files, the users can easily override these.

Rationale:

Group or world-writable user configuration files may enable malicious users to steal or modify other users' data or to gain another user's system privileges.

Audit:


# for dir in \

`logins -ox | awk -F: '($8 == "PS") { print $6 }'`; do

find ${dir}/.[A-Za-z0-9]* \! -type l \

$ -perm -20 -o -perm -02 $ -ls

done


Remediation:

Correct or justify any items discovered in the Audit step. Determine if any user hidden files are world-readable or writable, and work with those users to determine the best course of action in accordance with site policy.

9.9 Check Permissions on User .netrc Files (Scored)


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Level 1

Description:

While the system administrator can establish secure permissions for users' .netrc files, the users can easily override these.

Rationale:

.netrc files may contain unencrypted passwords that can be used to attack other systems.

Audit:


# for dir in \


find ${dir}/.netrc -type f $ \

-perm -g+r -o -perm -g+w -o -perm -g+x -o \

-perm -o+r -o -perm -o+w -o -perm -o+x $ \

-ls 2>/dev/null

done


Remediation:

Correct or justify any items discovered in the Audit step. Determine if any user .netrc files are group- or world-readable or writable, and work with those users to determine the best course of action in accordance with site policy.

9.10 Check for Presence of User .rhosts Files (Scored)


Level 1

Description:

While no .rhosts files are shipped with Solaris, users can easily create them.

Rationale:

This action is only meaningful if .rhosts support is permitted in the file /etc/pam.conf. Even though the .rhosts files are ineffective if support is disabled in /etc/pam.conf, they may have been brought over from other systems and could contain information useful to an attacker for those other systems.

Audit:

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# for dir in \


find ${dir}/.rhosts -type f -ls 2>/dev/null

done


Remediation:

Correct or justify any items discovered in the Audit step. Determine if any user .rhosts files are present in user directories and work with those users to determine the best course of action in accordance with site policy.

9.11 Check Groups in passwd(4) (Scored)


Level 1

Description:

Over time, system administration errors and changes can lead to groups being defined in passwd(4) but not in group(4).

Rationale:

Groups defined in passwd(4) but not in group(4) file pose a threat to system security since group permissions are not properly managed.

Audit:


# logins -xo | awk -F: '($3 == "") { print $1 }'


Remediation:

Correct or justify any items discovered in the Audit step. Determine if any groups are in passwd(4)but not in group(4), and work with those users or group owners to determine the best course of action in accordance with site policy.

9.12 Check That Users Are Assigned Home Directories (Scored)


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Level 1

Description:

passwd(4) defines a home directory that each user is placed in upon login. If there is no defined home directory, a user will be placed in / and will not be able to write any files or have local environment variables set.

Rationale:

All users must be assigned a home directory in passwd(4).

Audit:

This following check is to make sure each user has a home directory defined in passwd(4).

# logins -xo | while read line; do

user=`echo ${line} | awk -F: '{ print $1 }'`

home=`echo ${line} | awk -F: '{ print $6 }'`

if [ -z "${home}" ]; then

echo ${user}

fi

done


Remediation:

Correct or justify any items discovered in the Audit step. Determine if there exists any users who are in passwd(4) but do not have a home directory, and work with those users to determine the best course of action in accordance with site policy.

9.13 Check That Defined Home Directories Exist (Scored)


Level 1

Description:

Users can be defined to have a home directory in passwd(4), even if the directory does not actually exist.

Rationale:

If the user's home directory does not exist, the user will be placed in "/" and will not be able to write any files or have local environment variables set.

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Audit:





if [ ! -d "${home}" ]; then

echo ${user}

fi

done

[Only uucp and nuucp should generate errors (as their home directories do not

exist. Other entries should be verified for correctness.]

Remediation:

Correct or justify any items discovered in the Audit step. Determine if there exists any users whose home directories do not exist, and work with those users to determine the best course of action in accordance with site policy.

9.14 Check User Home Directory Ownership (Scored)


Level 1

Description:

The user home directory is space defined for the particular user to set local environment variables and to store personal files.

Rationale:

Since the user is accountable for files stored in the user home directory, the user must be the owner of the directory.

Audit:





find ${home} -type d -prune \! -user ${user} -ls

done

[Only uucp and nuucp should generate errors (as their home directories do not exist.

Other entries should be verified for correctness.]

Remediation:

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Correct or justify any items discovered in the Audit step. Determine if there exists any users whose home directory is not properly owned, and work with those users to determine the best course of action in accordance with site policy.

9.15 Check for Duplicate UIDs (Scored)


Level 1

Description:

Although the useradd program will not let you create a duplicate User ID (UID), it is possible for an administrator to manually modify passwd(4) and change the UID field.

Rationale:

Users must be assigned unique UIDs for accountability and to ensure appropriate access protections.

Audit:


# logins -d


Remediation:

Correct or justify any items discovered in the Audit step. Determine if there exists any users who share a common UID, and work with those users to determine the best course of action in accordance with site policy.

9.16 Check for Duplicate GIDs (Scored)


Level 1

Description:

Although the groupadd program will not let you create a duplicate Group ID (GID), it is possible for an administrator to manually modify group(4) and change the GID field.

Rationale:

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User groups must be assigned unique GIDs for accountability and to ensure appropriate access protections.

Audit:


# getent group | cut -f3 -d":" | sort -n | uniq -c |\

while read x ; do

[ -z "${x}" ] && break

set - $x

if [ $1 -gt 1 ]; then

grps=`getent group | nawk -F: '($3 == n) { print $1 }' n=$2 | xargs`

echo "Duplicate GID ($2): ${grps}"

fi

done


Remediation:

Correct or justify any items discovered in the Audit step. Determine if there exists any duplicate group identifiers, and work with each respective group owner to remediate this issue and ensure that the group ownership of their files are set to an appropriate value.

9.17 Check That Reserved UIDs Are Assigned to System Accounts (Scored)


Level 1

Description:

Traditionally, Unix systems have established "reserved" UIDs (0-99 range) intended for system accounts.

Rationale:

If a user is assigned a UID that is in the reserved range, even if it is not presently in use, security exposures can arise if a subsequently installed application uses the same UID.

Audit:


# logins -so | awk -F: '{ print $1 }' | while read user; do

found=0

for tUser in adm aiuser bin daemon dhcpserv dladm ftp \

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gdm listen lp mysql netadm netcfg noaccess \

nobody nobody4 nuucp openldap pkg5srv postgres \

root smmsp svctag sys unknown uucp upnp \

webservd xvm zfssnap; do

if [ ${user} = ${tUser} ]; then

found=1

fi

done

if [ $found -eq 0 ]; then

echo "Invalid User with Reserved UID: ${user}"

fi

done


Remediation:

Correct or justify any items discovered in the Audit step. Determine if there are any accounts using these reserved UIDs, and work with their owner to determine the best course of action in accordance with site policy.

9.18 Check for Duplicate User Names (Scored)


Level 1

Description:

Although the useradd program will not let you create a duplicate user name, it is possible for an administrator to manually modify passwd(4) and change the user name.

Rationale:

If a user is assigned a duplicate user name, it will create and have access to files with the first UID for that username in passwd(4). For example, if "test4" has a UID of 1000 and a subsequent "test4" entry has a UID of 2000, logging in as "test4" will use UID 1000. Effectively, the UID is shared, which is a potential security problem.

Audit:


# logins -d


Remediation:

Correct or justify any items discovered in the Audit step. Determine if there are any duplicate user names, and work with their respective owners to determine the best course of action in accordance with site policy.

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9.19 Check for Duplicate Group Names (Scored)


Level 1

Description:

Although the groupadd program will not let you create a duplicate group name, it is possible for an administrator to manually modify group(4) and change the group name.

Rationale:

If a group is assigned a duplicate group name, it will create and have access to files with the first GID for that group in group(4). Effectively, the GID is shared, which is a security risk.

Audit:


# getent group | cut -f1 -d":" | sort -n | uniq -c |\

while read x ; do

[ -z "${x}" ] && break

set - $x

if [ $1 -gt 1 ]; then

gids=`getent group |\

nawk -F: '($1 == n) { print $3 }' n=$2 | xargs`

echo "Duplicate Group Name ($2): ${gids}"

fi

done


Remediation:

Correct or justify any items discovered in the Audit step. Determine if there are any duplicate group names, and work with their respective owners to determine the best course of action in accordance with site policy.

9.20 Check for Presence of User .netrc Files (Scored)


Level 1

Description:

The .netrc file contains data for logging into a remote host for file transfers via FTP.

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Rationale:

The .netrc file presents a significant security risk since it stores passwords in unencrypted form.

Audit:


# for dir in \


ls -l ${dir}/.netrc 2>/dev/null

done


Remediation:

Correct or justify any items discovered in the Audit step. Determine if any .netrc files exist, and work with the owner to determine the best course of action in accordance with site policy.

9.21 Check for Presence of User .forward Files (Scored)


Level 1

Description:

The .forward file specifies an email address to which a user's mail is forwarded.

Rationale:

Use of the .forward file poses a security risk in that sensitive data may be inadvertently transferred outside the organization. The .forward file also poses a secondary risk as it can be used to execute commands that may perform unintended actions.

Audit:


# for dir in \


ls -l ${dir}/.forward 2>/dev/null

done


Remediation:

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Correct or justify any items discovered in the Audit step. Determine if any .forward files exist, and work with the owner to determine the best course of action in accordance with site policy.

9.22 Find World Writable Files (Not Scored)


Level 1

Description:

Unix-based systems support variable settings to control access to files. World-writable files are the least secure. See the chmod(2) man page for more information.

Rationale:

Data in world-writable files can be read, modified, and potentially compromised by any user on the system. World-writable files may also indicate an incorrectly written script or program that could potentially be the cause of a larger compromise to the system's integrity.

Audit:




-o -fstype proc \) -prune -o -type f -perm -0002 -print


Note: The script above does a file transversal of all files under the "/" directory, including NFS attached file systems, so running this search command may take quite some time.

Remediation:

Correct or justify any items discovered in the Audit step. Determine the existence of any "write access" given for the "other" category (chmod o-w <filename>), and work with the owner to determine the best course of action in accordance with site policy.

9.23 Find SUID/SGID System Executables (Not Scored)


Level 1

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Description:

The owner of a file can set the file's permissions to run with the owner's or group's permissions, even if the user running the program is not the owner or a member of the group. The most common reason for a SUID/SGID program is to enable users to perform functions (such as changing their password), which requires root privileges.

Rationale:

There are valid reasons for SUID/SGID programs, but it is important to identify and review such programs to ensure they are legitimate.

Audit:




-o -fstype proc \) -prune -o -type f -perm -4000 -o \

-perm -2000 -print


Note: The script above does a transversal of all files under the "/" directory, including NFS attached file systems, so running this search command may take quite some time.

Remediation:

Correct or justify any items discovered in the Audit step. Determine the existence of any set-UID programs that do not belong on the system, and work with the owner (or system administrator) to determine the best course of action in accordance with site policy. Digital signatures on the Solaris Set-UID binaries can be verified with the elfsign utility, such as this example:

# elfsign verify -e /usr/bin/su

elfsign: verification of /usr/bin/su passed.

9.24 Find Un-owned Files and Directories (Scored)


Level 1

Description:

Sometimes when administrators delete users from the password file they neglect to remove all files owned by those users from the system.

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Rationale:

A new user who is assigned the deleted user's user ID or group ID may then end up "owning" these files, and thus have more access on the system than was intended.

Audit:




-o -fstype proc \) -prune -o $ -nouser -o -nogroup $ -ls


Note: The script above does a transversal of all files under the "/" directory, including NFS- attached file systems, so running this search command may take quite some time.

Remediation:

Correct or justify any items discovered in the Audit step. Determine the existence of any files that are not attributed to current users or groups on the system, and determine the best course of action in accordance with site policy. Note that the Solaris OS is shipped with all files appropriately owned.

9.25 Find Files and Directories with Extended Attributes (Scored)


Level 1

Description:

Extended attributes are implemented as files in a "shadow" file system that is not generally visible via normal administration commands without special arguments.

Rationale:

Attackers or malicious users could "hide" information, exploits, etc. in extended attribute areas. Since extended attributes are rarely used, it is important to find files with extended attributes set.

Audit:


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-o -fstype ctfs\ -o -fstype mntfs -o -fstype objfs \

-o -fstype proc \) -prune -o -xattr -ls


Note: The script above does a transversal of all files under the "/" directory, including NFS- attached file systems, so running this search command may take quite some time.

Remediation:

Correct or justify any items discovered in the Audit step. Determine the existence of any files having extended file attributes, and determine the best course of action in accordance with site policy. Note that the Solaris OS does not ship with files that have extended attributes.

10 Appendix A: Additional Security Notes

The items in this section are security configuration settings that have been suggested by several other resources and system hardening tools. However, compared to the other settings in this document, the settings presented here provide relatively little incremental security benefit. Nevertheless, none of these settings should have a significant impact on the functionality of the system, and some sites may feel that the slight security enhancement of these settings outweighs the (sometimes minimal) administrative cost of performing them.

None of these settings will be checked by the automated scoring tool provided with the benchmark document. They are purely optional and may be applied or not at the discretion of local site administrators.

10.1 SN.1 Restrict access to suspend feature (Not Scored)


Level 2

Description:

Solaris 11 does not enable the suspend capability by default and now uses the poweradm command to suspend the system.

Rationale:

Bear in mind that users with physical access to a system can simply remove power from the machine if they are truly motivated to take the system off-line, and granting the

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capability to use poweradm may be a more graceful way of allowing desktop users to shut down their own machines.

Audit:


# poweradm list | grep suspend

suspend/suspend-enable smf=false, current=false

Remediation:


# poweradm set suspend-enable=false

# poweradm update

10.2 SN.2 Remove Support for Internet Services (inetd) (Not Scored)


Level 2

Description:

If the actions in this section result in disabling all inetd-based services, then there is no point in running inetd at boot time.

Rationale:

If inetd-based services are ever re-enabled in the future it will be necessary to re-enable the inetd daemon as well ("svcadm enable svc:/network/inetd:default").

Audit:


# svcs -Ho state svc:/network/inetd

disabled

Remediation:


# svcadm disable svc:/network/inetd

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Appendix: Change History

Date Version Changes for this version

06-11-2012 1.0.0 Initial Public Release 09-30-2013 1.1.0 Added recommendation 2.13 (Ticket #87)

09-30-2013 1.1.0 Removed Solaris11_scripts.tar References (Ticket #64)

09-30-2013 1.1.0 Altered recommendation 2.2 to recommend setting local only mode (Ticket #56)

09-30-2013 1.1.0 Updated 2.1 audit to clarify passing conditions (Ticket #54)

CIS Oracle Solaris 11 Benchmark - paper.bobylive.com

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